What are the three standardized tests used by officers to determine if a suspect is impaired?


Conducting Your Own
Field Sobriety Test
This assignment will give you the opportunity to conduct your own Field
Sobriety Tests (FSTs). As outlined in your text, there are three standardized
tests used by an officer to determine if a suspect is impaired. Select one of
the following learning activities on which to base this assignment:
Using the three standardized tests, conduct mock FSTs.
Evaluate your ability to perform the tests and any issues you feel these
tests might provide in determining if someone is under the influence.
Knowing what you know about ethanol and blood alcohol concentration, how
would you explain in court what it means to be driving under the
influence? Document your findings in a two-page paper; include a
brief detailing of each of the field sobriety tests, describe your
ability to perform the tests, evaluate field sobriety tests as a
persuasive means of proving impairment by alcohol, and explain the
weaknesses of using field sobriety tests in court to prove alcohol
impairment. 2. Watch the video, Top 3 Sobriety Tests number 2,
of an officer initiating a traffic stop of a suspected drunk driver and
the officer’s attempted evaluation of the driver. Document the manner in
which she performed these tests. Knowing what you know about ethanol and
blood alcohol concentration, how would you explain in court what it means
to be driving under the influence? Document your findings in a two-page paper; include a
brief detailing of the field sobriety tests, describe the ability of the
driver to perform the tests assigned, evaluate field sobriety tests as a
persuasive means of proving impairment by alcohol, and explain the
weaknesses of using field sobriety tests in court to prove alcohol
The assignment
must be formatted according to the APA style as outlined in the Ashford Writing
Center. Cite your resources in text and on the Reference page, as appropriate.
For information regarding APA samples and tutorials, visit the Ashford Writing
Center, located within the Learning Resources tab on the left navigation
Forensic Toxicology
Learning Objectives
After reading this chapter, you should be able to do the following:
Describe the types of cases that toxicologists analyze.
Identify different poisons and how they are sampled.
Explain how officers recognize drugs and alcohol in the field and how they
obtain samples for the toxicologist.
Discuss how toxicologists test blood and urine samples for drugs and alcohol.
Describe the drugs used in drug facilitated sexual assault and how they are
Explain the purposes of forensic urine drug testing and how it is done.
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oisons have been present throughout human history. Poisoning can be accidental. For instance, someone can eat the wrong plant, mushroom, or fish, and die.
However, poisonings can also be planned. Poisons derived from plant extracts
have been used in executions; Socrates suffered this fate. He was found guilty of crimes
against the state and was given a cup of hemlock to drink. In the past, if you wanted to
kill an enemy, there were preparations available that could complete the task. Today,
poisons are not used as often as instruments of homicide. However, methods of analysis
have been found that can determine the presence of toxins in the body and can assist the
courts in determining if a person was indeed poisoned, or under the influence of a toxin
or intoxicating compound.
In todays world, we come in contact with tens of thousands of chemicals. Many are not
harmful, but there are many others that are. We discussed drugs in Chapter 3, so we are
aware that drugs can cause death if taken in overdose quantities. In fact, nearly every
drug can be fatal if enough is consumed. Essentially, this makes almost every drug a poison. Even consumption of excessive water can deplete essential electrolytes in the body
and cause death.
An interesting point can be derived from this knowledge: It is the dose that makes a poison. This means that if taken in small enough amounts, some poisons can be used as
drugs. This has been the case for many years. For example, arsenic was previously used
to control rats and other vermin populations, but was also used at one time in some Chinese homeopathic medicines in very low doses. Anti-cancer drugs are poisons that are
designed to kill many cancer cells while killing relatively few healthy cells. Toxicology,
therefore, is the study of drugs and poisons or toxins and the way they affect the body.
When these studies and the information gained from the analysis of samples can be used
in court cases to help the trier of fact come to a conclusion about that case, the science is
known as forensic toxicology.
1. Forensic toxicologists can work on cases involving driving under the influence of
alcohol (DUI) or driving under the influence of drugs (DUID).
a. True
b. False
2. If a small amount of poison is administered over a long period of time, it is considered chronic dosing.
a. True
b. False
3. The breathalyzer test will be used if alcohol is thought to be present without
other drugs to determine breath alcohol concentration (BrAC).
a. True
b. False
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Section 4.1 Toxicology Cases
4. A blood sample submitted for DUI will be tested to find if ethanol is present and
quantitatively tested to find the amount present.
a. True
b. False
5. Sexual assault nurse examiners (SANE) can also complete toxicology lab testing.
a. True
b. False
6. If a person tries to hide drugs in their urine by some method, it is considered
a. True
b. False
1. a. True. The answer can be found in Section 4.1.
2. a. True. The answer can be found in Section 4.2.
3. a. True. The answer can be found in Section 4.3.
4. a. True. The answer can be found in Section 4.4.
5. b. False. The answer can be found in Section 4.5.
6. a. True. The answer can be found in Section 4.6.
4.1 Toxicology Cases
orensic toxicologists always have a monumental task before them in finding toxic
substances and poisons in the body, quantitating the level in the system, and determining possible effects, such as the increasing amount of impairment as a person
consumes more alcohol and
raises their Blood Alcohol Content (BAC). The toxicologist
will usually engage in analysis
of two types of cases. The first
type involves poisonings, both
accidental and intentional. The
second type involves people
who use illicit drugs in a recreational manner or victims who
have been given drugs without
their knowledge. Those involve
issues in which humans are
under the influence of one or
more compounds that impair
their ability to perform tasks
(human performance cases). Forensic toxicology work requires careful analysis and attention
Such cases are typical for the to detail, as the results found play a huge factor in determining
forensic toxicologist and involve drug and poison levels in a persons body.
driving under the influence of
alcohol (DUI) or driving under
Associated Press
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Section 4.2 Poisons
the influence of drugs (DUID). The toxicologist performs analyses that can find many
more compounds than the drug chemist. A toxicologist also searches for compounds in
blood, urine, or other biological samples, where the concentration of compound present is
in the parts per million range, and the interfering components in the sample can be in the
hundreds. In comparison, a drug chemist looks for a drug in a tablet, capsule, powder, or
plant material, where the amount of drug is determined as a percentage of the total weight
of the sample, and there are relatively few interfering compounds or diluents. Another
factor in a toxicologists work is metabolism, which is the bodys way of breaking down
a poison or drug into compounds called metabolites, which are compounds that can be
eliminated from the body. If metabolism has progressed far enough, the original drug or
toxin will not be found in the body. Instead, the analyst must search for a metabolite of
the drug. In order to complete that act, the drug usually is made more water soluble so
it can be deposited in the urine. Once in the urine, it can be eliminated from the body. Of
course, there are other ways to get rid of the drug, but transforming it into a metabolite for
removal is the most common. As we will see, all of these factors make forensic toxicology
a very interesting job.
The majority of cases submitted for forensic toxicological analysis will include two classes
of poisons. Those classes are 1) drugs of both the licit and illicit kind, and 2) volatile substances, such as ethanol and inhalants. Others that may be encountered to a much lesser
extent include gases, metals, pesticides, and other miscellaneous compounds. All of these
cases will make their way to a forensic toxicology laboratory from a coroners or medical
examiners office and through law enforcement personnel.
Think About It
While many forensic toxicology cases involve DUI and DUID, and these seem like pretty
straightforward trials, forensic toxicologists spend a great deal of time in court. Why do you
think they are called to court so often?
4.2 Poisons
istorical poisons are encountered by the forensic toxicologist on a limited basis,
but there are several types of poisons. Most will likely be seen in general circumstances. Heavy metals, such as arsenic, mercury, and lead, are often encountered
by people because of accidental ingestion. There have been cases of homeowners removing lead-based paint with hair dryers without adequate ventilation; these people have
come down with lead poisoning from inhaling the fumes generated by the heat of the
hair dryer. Children have succumbed to lead poisoning from eating chips of lead-based
paint. Family members and their pets have experienced arsenic poisoning after contact
with older rat poisons. Other metals, such as thallium, cadmium, cobalt, and selenium, are
included in this class, though they are not often encountered or easily obtained and would
most likely be involved in a case of intentional poisoning.
In these cases, blood and urine samples can be tested by the toxicologist. The principal
test utilized is atomic absorption spectroscopy (AA), which is sensitive to the g/L level.
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Section 4.2 Poisons
Scientists measure everything in metric system units. means micro, or one-millionth.
g stands for grams. There are about 28 grams in an ounce. L means liter, which is
around a quart.
New testing methods have made it possible for other samples to be tested. Hair testing for
some of the heavy metals, though not lead, can allow the toxicologist to determine if the
dosing was acute, or one time only, or whether it happened over a period of time, called
chronic dosing. Analysis of tissue samples post mortem would also be completed using
AA, and it could be used to quantitate the level in the body to determine if it was metal
poisoning that killed the victim.
Think About It
Even though some murderers use poison, it is rare today. Why do you think people have
moved away from the use of poisons to kill?
Recall from Chapter 1 that Mathieu Josef Bonaventure Orfila is often called the father of
forensic toxicology. In 1840, Dr. Orfila became involved in one of the most famous (or
infamous) cases of murder-by-poisoning in history, in which Marie Lafarge was convicted
of poisoning her husband Charles with arsenic.
Case Illustration: Toxicology and MurderIn the Beginning: The LeFarges
Marie married Charles Lafarge in 1839. The marriage was brokered, but Marie didnt know it at
the time. Although she did not come from an aristocratic background, she had been sent to the best
schools and had moved in the best circles, and she
felt entitled to marry a rich nobleman. She agreed
to marry Charles under the mistaken impression
that he owned property and had a successful business. In fact, he was marrying Marie for her dowry,
to help pay down his debts.
Mary Evans Picture Library/Everett Collection
They moved to a property owned by Charles,
where they lived in a rundown house. She was
quickly disillusioned about this arrangement. She encouraged Charles to go to Paris to try to
raise money. She wrote him letters of introduction and tried to make use of her former contacts to assist in this task. While he was away in Paris, Marie wrote him love letters, sent him
her picture, and also sent him a Christmas cake. After eating a piece of it, he became violently
ill. He discarded the remainder of the cake, and tried to rest and regain enough strength to
return home. He did not think about seeing a doctor, as he thought the cake had spoiled in
transit. He still did not feel well after returning home. Marie prepared his meals during this
time, and he again fell ill. The family doctor thought the symptoms were cholera-like, and
was not suspicious when Marie asked him for a prescription for arsenic to kill the rats that
were disturbing Charles at night.
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Section 4.2 Poisons
Case Illustration: Toxicology and MurderIn the Beginning: The LeFarges (continued)
Charles health deteriorated rapidly and he eventually died. His family, and others who had
come to keep watch and help him, became suspicious of Marie. She had been observed stirring a white powder into food and drink intended for Charles. A doctor that was consulted
close to the time Charles died began to suspect poisoning, but it was too late.
One of Charles brothers, whose suspicions had been aroused, contacted the local police, and
a magistrate came to do an inquiry. He took possession of some food items that remained,
which could contain a poison. He learned that Marie had purchased arsenic not long before
Charles had received the cake in Paris, and again after he returned home. Maries gardener
confirmed that she had given him arsenic to make a paste to kill rats. This paste was found
around the house, but it did not appear to have been disturbed by rats. The magistrate also
asked Charles local doctors if they could perform a new test for arsenic that he had heard
about: the Marsh test. The doctors agreed, but did not know about the tests intricacies. They
used older methods to test Charles stomach contents taken at autopsy, and obtained inconclusive results. Nevertheless, they reported arsenic present. One of the people tending to
Charles had taken Maries box, from which people had seen her taking the white powder for
Charles food and drink, and it was turned over to the magistrate. Arsenic was found in the
box. In addition, the arsenic paste that had been placed in the house for the rat problem was
found to be a mixture of flour, water, and baking soda.
Marie was put on trial for murder. One of Maries lawyers knew Dr. Orfila. He submitted the
local doctors arsenic testing results to Orfila and asked for an opinion. Orfila submitted an
affidavit to the trial court stating that the tests had been conducted poorly and that the result
meant nothing. When the local doctors testified about the arsenic in Charles body, the lawyer read Orfilas affidavit informing the court about the Marsh test and insisted that he be
called to do the test and as a witness. Prosecutors were confident of Maries guilt and said
they would agree to the testing, but did not see the necessity of calling Orfila (who was the
acknowledged expert on the Marsh test in Europe at the time). The judge agreed, and ordered
that local pharmacists conduct the testing. They reported not finding any arsenic in the stomach contents taken at autopsy. Charles body was then exhumed and new specimens taken.
The pharmacists again failed to find arsenic. Marie seemed to be vindicated. However, the
prosecutor learned from Orfilas writings that arsenic can leave the stomach through normal
digestive processes and thus not be present in the contents. He also remembered the saved
food items that Marie had given to Charles. He asked that they be tested. The defense, now
confident about their case, agreed. This time, though, the pharmacists came back and said
there was a large amount of arsenic in the food items. The prosecutor again asked the judge
to permit Orfila to come in and settle the matter, since there had been contradictory results.
The defense more or less had to agree to this, having consulted Orfila first. Orfila conducted
his tests in the presence of the pharmacists, and found that arsenic was present in specimens
taken from Charles body. The defense team sought to call an opposing expert, Franois Raspail, who had opposed Orfila in court at other times. Unfortunately for Marie, Raspail was
late, and the trial ended. Marie was convicted and sentenced to life imprisonment. Marie,
suffering from tuberculosis, was released in 1852, but died the same year.
Reflect On It
In what ways do you think this case would be different today, in terms of determining the
presence of arsenic in Charles body, the court proceedings, and the verdict?
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Section 4.2 Poisons
This was a spectacular case in the annals of criminal justice. People were divided on
whether Marie was guilty or not. It was also one of the first cases pitting experts against
one another in the courtroomsomething that is quite common today.
Poisoning is now infrequent in murder cases. A couple of centuries ago, it was used often
by the aristocracy to get rid of their enemies. A modern murder by poison took place in
2000 in San Diego, California. This case is intriguing because it involves employees of the
medical examiners forensic toxicology laboratory.
Case Illustration: Toxicology and MurderModern Day: Rossum v. Patrick
Kristin Rossum was accused and convicted of poisoning her
husband, Greg, using fentanyl she had stolen from the medical examiners toxicology laboratory, where she worked as a
toxicologist. As you may recall from Chapter 3.4, fentanyl is
a synthetic narcotic analgesic, about 100 times more potent
than morphine.
Kristin worked in the San Diego County Sheriff/Coroner
Toxicology Laboratory. At some point, she began an affair
with Michael Robertson, the Chief of Toxicology, who was
also married at the time. Kristin was a drug abuser who
stole drugs from the workplace to feed her habit. Kristins
husband Greg learned about the affair and threatened to
expose her and her drug use if she did not quit her job.
Associated Press
On the day of Gregs death, Kristin called 911. Responding
paramedics found her in the middle of the living room. His body had been sprinkled with red
rose petals and a wedding picture had been placed nearby, a setting similar to a scene from
one of Kristins favorite movies. Kristins credit card had been used to buy a similar rose. They
took Greg to a hospital, where he was pronounced dead.
Police questioned Kristin weeks after Gregs death. There was a conflict of interest with the
toxicology laboratory at her place of employment, so the toxicology testing of specimens from
Gregs body was outsourced. The lab reported high levels of fentanyl (above fatal levels) along
with clonazepam and oxycodone at therapeutic levels (both of these drugs are legal by prescription). The investigation went on to uncover Kristins methamphetamine use, and a large quantity
of fentanyl missing from the coroners office. Kristin was charged with and tried for murder; the
states allegation was that she killed Greg by administering to him a fatal dose of fentanyl.
The evidence was circumstantial, but Kristin was convicted. The defense had argued that Greg
was suicidal and had poisoned himself. The jury did not agree. Kristin was sentenced to life
without the possibility of parole.
Kristin appealed for a new trial in federal court, but was turned down. She then appealed to
the Ninth Circuit Court of Appeals. A three-judge panel of that court was ready to reverse the
lower court and grant her petition, but they withdrew their opinion and replaced it with a
one-paragraph statement that a newly decided U.S. Supreme Court case, Harrington v. Richter
(2011), controlled their decision.
Kristins appeal was based on ineffective counsel at trial. The argument runs that her defense
attorneys should have pursued some toxicological issues that they did not,
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Section 4.2 Poisons
Case Illustration: Toxicology and MurderModern Day: Rossum v. Patrick (continued)
and which, if they had, might have resulted in a different outcome. One issue is whether the
admittedly sub-lethal quantities of clonazepam and oxycodone found in Gregs body might
have caused his death by way of synergistic drug actionacting together in a way that was
more powerful than that of either drug separately at the same levels. Another issue raised on
appeal was the possibility that the fentanyl was administered post mortem. An expert hired by
Kristin noted that the post mortem specimens were not tested for fentanyl metabolites, and,
as a result, it was not certain that he had ingested the drug before his death.
Reflect On It
Was there sufficient evidence to convict Kristin Rossum of poisoning Greg? Why or why not?
Pesticides are not usually seen in forensic toxicology cases. A common class of pesticides
is the organophosphates; these compounds include parathion and diazanon. Most of these
cases involve accidental exposures. Should a case be seen that is suspicious, blood and
urine samples can be analyzed in the forensic toxicology laboratory.
Chromatographic techniques can provide preliminary information about a sample
through separation of the different components of a mixture. If you put a drop of ink near
the bottom of a piece of paper and then dip the paper in water, the water will be absorbed
and travel up the paper. When the water hits the ink, some of the pigments will continue
upward with the water, while others remain behind. As the water continues to travel up
the paper, you can see separation of the ink pigments. This works the same way with
forensic samples when put through instrumentation that is often used. By separating a
mixture, such as urine, into its individual components, and comparing these to known
pesticides, we can say that a pesticide could be present in the urine, and, if so, it might be
a particular pesticide as opposed to many others.
Mass spectroscopy will then be used to conclusively identify the pesticide that was
ingested by the victim and found in the urine. Remember from the Chapter 3 that mass
spectroscopy can give molecular information that will allow the scientist to say without
doubt that a particular pesticide, such as malathion, is present, as opposed to any other
pesticide that exists. Hospitals can determine this class of compound is involved based
on symptoms, including salivation, lacrimation (tears), excessive urination, diarrhea,
nausea, and vomiting. Testing is then completed to determine if organophosphate class
compounds are present. Should the circumstances of the poisoning be suspicious, law
enforcement will be called. Samples should be collected with proper chain of custody and
sent to the forensic science laboratory.
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Section 4.2 Poisons
Carbon Monoxide
Carbon monoxide (CO) is encountered mainly in accidental deaths. This odorless, colorless gas binds to hemoglobin (the protein in red blood cells that carries oxygen) so tightly
that it cannot be easily displaced. As more and more hemoglobin is rendered useless by
binding to CO, oxygen deprivation will set in and can cause death. Most of the approximately 500 deaths in the United States each year are due to malfunctioning flame heaters
and a lack of CO detectors in homes, and they are termed unintentional deaths (Centers
for Disease Control, 2007, pp.
13091312). Suicide by CO poisoning using automobiles used
to be common, though this is
becoming less popular as other
methods of CO poisoning, such
as by charcoal, have been found
(Schmitt, Williams, Woodard,
& Harruff, 2011). Carbon monoxide is formed when organic
fuels are burned with too little
oxygen present to form carbon
dioxide (CO2). Levels of less
than 1.5% CO in the air can be
lethal within minutes. In the
lab, a CO-oximeter will be used
Accidental death by carbon monoxide poisoning can be
to determine the level of carprevented if people install CO alarms in their homes. Do you
boxyhemoglobin in the blood to
think it should be required for all people to have these?
determine if the cause of death
was CO poisoning.
Other Gases
Toxicology laboratories are encountering other gases in samples from law enforcement
agencies. Many of these submissions are due to intentional inhalation of various substances for the purposes of getting high. Included in this group are the inhalants discussed
in Chapter 3. These are the nitrites and nitrates; anesthetic gases like nitrous oxide and
halothane; and the fluoro- and chloro- carbon compounds, such as difluoroethane, found
in office supplies and pressurizers for food products. These compounds are easily purchased and abused. Users inhale the contents as they spray them from the can. The ingredients enter the bloodstream very quickly through the lungs. The effects are similar to
central nervous system depressants. An officer on the scene may find a user unresponsive,
but he or she will revive in minutes, and the compounds will clear from the bloodstream
very quickly. Due to the rapid clearing of the compounds from the system, obtaining
samples for prosecution of cases is difficult, as most of the drug will clear from the users
system on the way to a collection site, such as a hospital.
These compounds do not show up in breathalyzer testing and will not be seen in the
urine under normal testing, so a blood sample is best for cases involving inhalants. In the
laboratory, the sample will be tested using head-space gas chromatography with mass
spectroscopy. This is the same technique used to find ethanol in the blood; it can easily
differentiate and conclusively identify various inhalants for the courts.
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Section 4.2 Poisons
Illicit Drugs and Medications
Illicit drugs and medications are commonly seen in toxicology cases. These also involve
samples taken from living beings and samples taken post mortem. In the case of drugs, testing will include the use of chromatography of various types, color tests, and immunoassay
as the preliminary testing to determine the classes of drugs that might be present. Extraction
of the sample is completed to purify the sample. Final identification of the drugs is accomplished with mass spectroscopy as the conclusive test. Blood and urine samples are the most
common, though hair testing is on the rise. In post mortem cases, other samples will be
collected, including vitreous humor (fluid in the eye) and possibly tissue samples. While
collecting fluid from the eye may seem unusual or even disgusting, for the toxicologist, the
vitreous humor is a sample that is cleaner than samples like blood or even urine, because
there are fewer bacteria and interfering compounds contained in the fluid. These samples
will be collected by the medical examiner or forensic pathologist at autopsy.
The collection of gastric contents may seem like an obvious step from many of the forensic
television shows, but the forensic toxicologist will not usually look for the victims last
meal. Instead, he or she will look for drugs or poisons that may have been used acutely
to cause death. Sometimes, there will be the remnants of tablets or capsules in the gastric
sample. These are easily and quickly analyzed and can indicate what the toxicologist will
find in the blood. Additionally, gastric contents can be analyzed to find drugs of abuse
that are not in standard dosage forms. For instance, gamma-hydroxy butyric acid (GHB)
might be found in a victim who died shortly after administration of the drug.
Multiple blood samples are often taken at autopsy because of a phenomenon called post
mortem redistribution. This can be seen if the victim has been deceased for a period of
time, presenting the toxicologist with significant problems. Drug concentrations in organs
of the body will be higher than the blood concentration until absorption and distribution
take place. Upon death, this distribution cannot be completed. The drug will start diffusing through the body from the area of highest concentration toward a lower concentration. What this means is that a blood sample taken from the chest area might have a very
high concentration of a drug, because of redistribution from the gastrointestinal tract into
the bloodstream, while blood taken from the leg would have a lesser concentration. Toxicologists must be able to analyze all presented samples to determine how much redistribution has taken place and determine what might have been an effective concentration in
the blood when the victim died.
The toxicologist will usually begin with a screening of the urine sample to find out what
classes of drugs could be present. The reason for starting with urine is that after drugs are
taken in to the body, they are distributed through the blood to the tissues. After the drug
has acted on the body, it is metabolized and eventually delivered to the kidneys to collect
in the urine. Therefore, the urine will have a higher concentration of drug than the rest of
the body. This makes detection of drugs in urine much easier than in other body fluids
or tissues. Sampling for many immunoassay tests takes place directly on the urine with
little or no pre-treatment. Immunoassay tests can simultaneously test for many classes of
drugs, in very little time and with minimal sample use, allowing the toxicologist to determine what classes of drugs could possibly be present in the individual. These tests rely
on exposing a sample to reagents which react with drugs or the metabolites of drugs that
can be found in the urine after consumption of drugs. For instance, there is a reagent that,
in the presence of benzolyecgonine, a metabolite of cocaine, will give a reaction that can
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Section 4.3 Drug and Alcohol Recognition in the Field
be read by the instrument. The analyst can then determine if the sample should be tested
further to confirm the presence of cocaine and its metabolites. There are many reagents
which can test for a large variety of drugs of abuse. This testing is rapid and uses very
little of the sample.
At the same time the urine is screened for drugs, the blood can be tested for volatile substances such as ethanol, methanol, isopropanol, the inhaled gases, and acetone. The test
used for this analysis is called head-space gas chromatography. A sample of the blood is
added to a vial with a compound called an internal standard. This internal standard is a
compound that behaves on the instrument very much like the compounds the toxicologist
is analyzing. The internal standard is not likely to be found in a sample, for a variety of reasons, including the fact that it might not give a reaction in the body, or it is not yet approved
for use by the Food and Drug Administration, or it might act like the drug on the instrument while not actually being a drug. This compound helps standardize analysis so quantitation and identification can easily be completed. The sample with the internal standard is
sealed in its vial. The vial at this point is only partially filled, with significant air above the
liquid. This is the head-space. The vial is heated so a small amount of any volatile substance
can evaporate into the air above the liquid. Each volatile substance has a concentration that
will evaporate into the head-space relative to the concentration left in the blood at the temperature used to heat the sample. After heating and equilibration, a specific amount of the
head-space is withdrawn from the vial and placed onto the gas chromatograph. All of the
volatiles are separated in the gas chromatograph, and after passing through a detector, are
plotted on a graph. This graph will let the analyst determine the identity of the compound
based on the time it took to get through the column to the detector; it also allows the analyst
to quantitate the amount based on the size of the peak.
After this analysis, other samples taken from the blood may be used to quantitate other
drugs that may be present as indicated by the urine analysis. These tests require extractions of the blood to clean up the sample for analysis, followed by instrumental analysis
to identify and quantitate the amount of drug present in the blood. Remember, only the
drug in the blood has the ability to interact with tissues and let the drug have an effect.
The protocols discussed are used in the most common of toxicological cases, such as DUI
and DUID cases. Today, these cases constitute a majority of the samples seen by toxicologists. Make no mistake, poisonings and deaths are seen as well, but DUI and DUID cases
are the most common. How do these cases make it to the laboratory? The most common
route is through a traffic stop or an accident. Officers determine if alcohol or drugs may be
involved, and samples will generally be collected at a hospital and taken for testing by the
laboratory. But how is that determination made? This will be answered in the next section
on how to recognize drug and alcohol use in the field.
4.3 Drug and Alcohol Recognition in the Field
olice officers may receive training to recognize if drugs or alcohol might be present
in a person. Some states have what is called the Drug Recognition Expert (DRE)
program. Not all officers are trained as DRE. However, the program is expanding,
so more officers are receiving this training, which goes beyond the standard to enable
officers to determine when a suspect has used a drug, and what class of drug it could be.
Officers do not try to determine the specific drug, only a general group. The groups
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Section 4.3 Drug and Alcohol Recognition in the Field
include depressants (including alcohol), stimulants, hallucinogens, and also phencyclidine, opiate and narcotic drugs, cannabis, and inhalants. Officers will not consider common drugs, such as aspirin, in their determinations. They can only determine if an impairing,
abused drug might be present. The information gained by the officer at the scene can be
used by the toxicologist to assist in analysis. Remember, however, that the toxicologist will
only use this information as an aid. The analysis is not tailored to the results of the officers
investigation and report.
The following example will take us through a complete toxicology case where the charges
will be DUI and DUID. An officer responds to the scene of a simple accident, where a car
has struck a telephone pole. Upon questioning the driver, the officer notices what seems
to be the odor of an alcoholic beverage on the
drivers breath. Something to note is that ethanol
has no odor; instead, it is the other components of
the alcoholic beverage, such as tannins, oils, and
additives, that contribute to those smells. At this
point, the officer may ask the suspect to submit to
field sobriety tests. These are called in some circles psychophysical tests, or divided attention tests.
The officer is trying to determine if the suspect
could be impaired. The three tests normally used
in the standardized field sobriety tests (SFST)
are the walk and turn test, the one leg stand test,
and the finger to nose test (U.S. Department of
Transportation National Highway Traffic Safety
Administration, 2001).
Additionally, the suspect might be observed by
the DRE. Certain aspects of behavior and appearance indicate the possibility of drug use. These
include the way the suspect answers questions.
Does the person answer the officers question
or exhibit a stream of consciousness talking that
bears no relation to the question? Does the person
appear to be disheveled or unable to stay alert?
All of these characteristics can be used by the DRE
to determine if a suspect is under the influence
of a drug, and if so, the class to which that drug
One of the most familiar sobriety tests is
the walk and turn test. Do you think it is an
effective way to judge whether a person has
been drinking?
Associated Press
If the person being observed took a depressant, he or she may be lethargic and slow to
respond, or may fall asleep at inappropriate times. Officers have observed suspects who
were placed in a squad car fall asleep even after an accident. If the person being observed
has pinpoint pupils, this could indicate an opiate as opposed to any other depressant, as
most other depressants do not cause this condition. It is often very easy to determine if
inhalants are the problem. Remember, inhalants depress the central nervous system, causing drowsiness and sleep. Since these are so fast acting, there is usually evidence in the
immediate vicinity, such as the cans containing the gases. These should be collected as
evidence, because by the time officers take the person to a sample collection facility, he or
she will appear normal and the drug will have mostly cleared from the system.
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Section 4.3 Drug and Alcohol Recognition in the Field
If the person has taken stimulants, he or she may be very active and energetic, or, depending on the stimulant, uncooperative and argumentative. Hallucinogens can cause similar
symptoms, but the behavior of a person using this class of drug may be more bizarre and
their affect and response to questioning will be less coherent. The officer may check for
vertical gaze nystagmus, uneven tracking of the eye, if the presence of hallucinogens is a
possibility. The officer will ask the person to follow an object as it is moved up and down
in front of him or her. Normally, the eye can track smoothly. It has been found that people
using phencyclidine (PCP) cannot track smoothly up and down. This could let the DRE
know that the suspect has taken PCP and great care should be taken with the individual, as many PCP users have violent episodes. Additionally, PCP is an anesthetic, which
means the suspect will not feel pain normally. This can lead to a very dangerous situation
for officers and anyone else in the area. Other hallucinogens, including cannabis, do not
have this same effect.
If the suspect scores poorly on the SFST, the DRE may have a good indication of the drug
present in the suspect. He or she will be further interviewed and asked to take a
breathalyzer test if alcohol appears to be present without other drugs, or a blood and
urine test if there is an indication that drugs other than alcohol are present. Breathalyzer
test units today accurately record the alcohol concentration in the breath. There are many
restrictions for breathalyzer testing that are followed to make sure the test is accurate. The
individual being tested must be observed for twenty minutes prior to the test to ensure
that foreign materials have not been placed in his or her mouth and that he or she does not
belch or vomit. This rule was originally made for the protection of the suspect, to ensure
that no raw ethanol was in the suspects mouth. The presence of alcohol in the mouth
would falsely increase the breath alcohol concentration (BrAC).
The use of breathalyzer testing and the rules for the administration of the breath test
have been changed in recent years by the defense community. Defense attorneys have
tried to say, for instance, that
because a person had dentures,
his or her breathalyzer test was
invalid. This has given rise to
myths about beating the breathalyzer test, including the idea that
putting a penny in your mouth
can produce a bad result. While
it does not interfere with the test,
officers do need to be aware of
the fact that suspects may try to
hide items in their mouth.
Some bars are beginning to install breathalyzer machines on
their premises. Do you think these can help prevent people
from driving before they are sober?
Associated Press
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In addition, suspects are now
taken to a law enforcement facility for a breathalyzer test instead
of using a portable breathalyzer
test (PBT) unit in a squad car.
The PBT can be used for probable
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Section 4.3 Drug and Alcohol Recognition in the Field
cause, but not as final evidence in a court. The concern is that since the PBT is in a car and
exposed to bumps, accidents, and other factors, the calibration may not be correct and the
results may not always be accurate.
Instruments must be routinely checked for reliability and calibrated for accuracy. Test
administrators are trained to operate, function check, and administer the tests, as this
is one of the most routinely challenged aspects of DUI cases. All log books and calibration and function check data must be kept in order to meet these challenges. During the
observation period, the suspect will be asked more questions about health, use of alcohol
or drugs, and food consumption. This will be used in court and by the toxicologist. The
answers collected can allow the toxicologist to perform a back extrapolation, which we
will discuss later.
Think About It
From your knowledge of ethanol, why do you think the tests used in the Standardized Field
Sobriety Testing program help in the determination of alcohol use and impairment in the
Hospital Blood and Urine Samples
If the suspect agrees to a blood draw and gives a urine sample, or if the breathalyzer test
is negative, he or she will often be taken to a hospital for the draw and collection. Blood
draws are routine in the case of an accident. The routine hospital blood draw will allow
the hospital to test serum for alcohol. Serum is the fluid left behind when all of the blood
cells are removed. This process concentrates the alcohol in a smaller volume, making it
necessary to convert the serum alcohol concentration into a whole blood alcohol concentration. This is easily done, since many studies have concluded that the average serum
to whole blood conversion ratio for people is 1.18 to 1 (Charlebois, Corbett, & Wigmore,
1996). To convert, a toxicologist will divide the serum alcohol concentration by 1.18 and
obtain the whole blood alcohol concentration (BAC).
Sample Collection for the Toxicologist
In cases that involve DUI and DUID, chain of custody is assisted by the use of prepared
kits from various scientific companies, one of which is Tri-Tech, Inc. As you may remember from our discussion in Chapter 2, chain of custody applies to every kind of evidence,
and it must document who handled the evidence, who analyzed it, how it was treated,
any preparation done to the evidence before packaging, and where it was stored. Any
breaks in the chain of custody can result in the evidence being inadmissible in court.
The blood and urine samples for forensic toxicologists are separate from the hospital samples, and the use of the prepared kits is a necessity. The kits are sealed boxes containing
the paperwork and vials necessary for sample collection. When needed, the seal on the
box is broken to allow access to the contents. A typical kit contains two vacutainer tubes.
These will have gray tops and contain a preservative and an anticoagulant. The preservative keeps the blood from spoiling and the anticoagulant keeps the blood from clotting.
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Section 4.4 Toxicology Laboratory Testing
Both are necessary for the toxicologist to test the blood and arrive at a reliable BAC. There
are two labels for the blood tubes, on which the name of the suspect, the date and time,
the officers name, and the name of the individual drawing the blood are written. This can
then be placed on the tube to seal it.
The urine collection is accomplished using two plastic bottles in the kit. These bottles are
clean and dry and will provide enough sample for testing at the toxicology laboratory.
There are labels for these bottles similar to those for the blood tubes that can be used to
seal the bottles. The urine collection is accomplished while maintaining the dignity of the
suspect. This is often done by a same-sex officer accompanying the suspect to a restroom
prepared for sample collection. The suspect is searched to make sure he or she does not
have anything that could be used to contaminate the urine sample. The suspect has the
privacy of a stall, but the officer is outside to receive the sample immediately after it is
placed in the vial by the suspect.
Paperwork is included to provide a history of the incident, be it an accident or traffic stop;
suspect information, including medications being taken and possible drug or drinking
history; and a request from the officer to the laboratory indicating what analysis should be
completed. While the collection is taking place, the suspect will be examined and observed
by medical personnel who can help determine the possible drug class that was ingested
by the suspect. This information will be communicated to the officer and further discussion with the DRE may take place to arrive at the possible cause of impairment. The DRE
may compile enough information to write the report that can later be used in the trial.
When the collection is complete, there is a form for the toxicology laboratory that will let
the toxicologist know what is possibly in the blood and urine. Everything will be placed
back in the original box, sealed using a label, and sent to the toxicology laboratory.
Transportation of samples to a forensic laboratory should take place as soon as possible.
While storage at room temperature for a time is not harmful to the samples, care should
be taken to prevent exposure to extremes in temperature. Excessive heat, like storing the
samples in the trunk of a car on a hot summer day, will destroy the blood samples and
promote growth of bacteria in the urine. Excessive cold weather with temperatures below
freezing could cause the blood to freeze and shatter the tubes. Samples can be kept safely
in a refrigerator not used for food as long as proper chain of custody is kept and the refrigerator is in a secure area of the building.
4.4 Toxicology Laboratory Testing
nce the evidence has been received in the toxicology laboratory, it will be signed
into the laboratory and each item of evidence will be given a unique identifier.
This will prevent any sample mix-up in the future. The evidence will be stored in
a locked area under refrigeration. When it is to be analyzed, it will be moved to the testing area. The toxicologist will see the information from the officers observations and the
medical personnels evaluation. This can be used by toxicologists in their analysis to assist
in testing, but will not be the sole basis for their tests. Toxicology laboratories have welldocumented rules to determine who can direct a laboratory and who can do the testing
(SOFT/AAFS, 2006). The analysts must follow protocol when analyzing evidence. These
rules for analysis make sure complete and unbiased testing is done in each case presented.
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Section 4.4 Toxicology Laboratory Testing
One of the first rules is that the toxicologist should only sample from one blood tube and
one urine vial. The remaining sample should be kept in case the defense wants testing
completed by their toxicologist.
Analysis is always completed with control samples, as we discussed in Chapter 1.4.
These controls are a large part of the quality assurance and quality control process. They
are samples from the same matrix (blood or urine) that is being tested. There are several types of controls used in the toxicology laboratory. Positive controls have drugs
in them. Analysis of this control lets the toxicologist know that the procedure worked
as expected, and if drugs were in the suspect sample, they would be found. Negative
controls do not have drugs in them. These samples let the analyst know that the testing
worked and there was no contamination of samples in the extraction and testing process.
Quantitative controls are used if the sample is to be tested for the amount of drug present. These have a known amount of drug present and after completion of the analysis
using these controls, the analyst will know that the process worked and gave the correct
value of drug present. If all controls give their proper answer during analysis, the analyst knows the procedure worked from the first step in the extraction process all the way
through instrumental analysis.
Analysis of Cases
The analysis of other samples at the forensic toxicology laboratory is much the same as
those submitted for drug analysis. Preliminary tests indicating possible classes of drugs or
poisons that may be present are completed. Finding what is possibly present in a sample is
often referred to as qualitative testing. Preliminary testing includes use of color reagents
that react based on the possible presence of a drug. Different types of immunoassay
tests also provide preliminary information about the classes of drugs that may be present. These tests use a specially
designed antibody to react with
a drug in the urine or other
fluid. When a drug is present,
the reaction will yield a product
that can be detected and measured in the instrument, letting
the analyst know that a certain
drug or drug class is present
in the sample. After determining what class of drug might be
present, confirmatory testing
is done to conclusively identify
the drug or drugs present. Following this, testing to establish
the concentration of drugs in the
body can be completed. This is Samples at forensic toxicology laboratories are run through
called quantitative testing. In various tests for analysis, including immunoassay tests. Do you
every case, qualitative testing is think individual states should be allowed to determine what BAC
completed because the forensic level implies impairment?
toxicologist must report what
Associated Press
drugs or metabolites were in the
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Section 4.4 Toxicology Laboratory Testing
suspects system to the trier of fact. The completion of quantitative testing depends on the
type of case and the individual statutes of the state where the crime was committed.
In every DUI case, a quantitative test will be completed. Each state has a BAC that legally
establishes impairment. Because of this, the toxicologist must know the concentration for
testimony in court. In a case where a controlled substance is involved, some states have
what is called a per se law. This means that the toxicologist does not have to quantitate the
controlled substance that is present if it is termed a drug of abuse. This is because the per
se law deems that any amount of that substance found in the body classifies the suspect as
impaired. This includes drugs like cocaine, methamphetamine, phencyclidine (PCP), and
lysergic acid diethylamide (LSD). Many cases involve prescription drugs. Some of these
drugs may be controlled, as we saw in Chapter 3, but are not considered drugs of abuse.
In cases involving these drugs, toxicologists may quantitate the drugs present if a blood
sample is submitted. They will not be able to tell if the person was impaired but they can
obtain a level of drug in the blood. There are three general levels of drug in the body that
can be described.
A sub-therapeutic level of drug means that there were drugs in the persons system but the
level was low enough that the drug likely did not have an effect. This could be described
as a person who takes a depressant drug as a sleep aid. The next day, if he or she is
involved in an accident, there might be a small amount of the drug remaining in the body.
The toxicologist would find it, quantitate the drug and find that indeed, the level was so
low that the person was most likely not affected by the drug. The trier of fact could then
take that into consideration during deliberations and possibly find that the accident was
just an accident rather than an accident caused by an impaired person.
A therapeutic level of drug means the drug is in the persons system and is at a level where
the drug effects are present. Again, the toxicologist cannot say the person was impaired,
but he or she can say that the drug was present at a level where its effects could have been
a factor in a case. An example of this involves a person who takes a depressant drug and
tries to drive immediately after consumption. When the drug is distributed in the system,
the person dozes off in the car and is involved in an accident. The toxicologist quantitates
the drug and finds it to be in the therapeutic range. The toxicologist relays this to the court
and describes how the effects of the drug present themselves. The toxicologist says that
the levels of this depressant could cause drowsiness, decreased attention, slowed reflexes,
and relaxation. The police officer would need to fill in the details of how the suspect was
acting at the scene. If what the officer reveals and what the toxicologist describes are similar, the trier of fact could find that the person was impaired and reach a verdict reflective
of these facts.
The third level that a toxicologist looks at is the lethal level, to see if there is enough drug
in the system to kill the individual. This usually involves post mortem toxicology. For
example, a body is found with pill vials nearby, or a body is found with a syringe and
packet containing illegal drugs. In either case, the toxicologist identifies the drug in the
body, and quantitates to find if the level present was at or above the lethal level. If so, it
would be reported and would help the coroner or medical examiner reach a conclusion
about the cause and manner of death in the case. Toxicology testing takes time. That is
why you may have noticed that in high-profile cases, the medical examiner or coroner
waits for the toxicology results to come back before making statements about the cause of
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Section 4.4 Toxicology Laboratory Testing
death. One must note that not everyone will die just because there is a high concentration
of drug in their system. Many addicts can survive a level that would be lethal to a novice
user because they have developed tolerance to the drug. This does not indicate lack of
impairment; it only indicates that they can take higher doses of drugs and not die.
Think About It
The per se law states that the presence of an abused drug, no matter the quantity, renders the
person impaired. Do you think this is a fair law? Why or why not?
We have discussed the entire process from first observation by the officer through analysis
by the toxicologist. However, what does this testing mean for the law enforcement officer,
victim, and suspect? Through analysis, the toxicologist can identify drugs and ethanol in
the provided samples. A report of these findings is sent to the law enforcement agency
that submitted the case. If no drugs or ethanol are found, the case may be dismissed. If
drugs are found, the suspect may be charged with DUID. If the drugs found fall under the
abused drugs list, then any per se law goes into effect. In other words, the mere presence
of drugs in the suspects samples indicates impairment. If prescription drugs are found
and quantitated, the toxicologist will testify at trial as to what the level means in normal
people. This seems very simple; however, there are other toxicological issues that can
come into play. Remember that drugs are metabolized in the body. These metabolites may
be inactive but may remain in the blood or urine longer than the active parent drug.
Lets take cocaine as an example. Remember, cocaine is a controlled substance. It is a
stimulant and can cause a decrease in judgment and inhibitions that can lead to accidents
or improper behavior. Cocaine is metabolized to benzoylecgonine, an inactive compound
that remains in the body for a while after the cocaine has disappeared. If the analyst only
finds the metabolite, does this mean the person was not impaired? The defense will certainly try to present this point. The analyst must remain unbiased in the case. The analyst
can state that benzoylecgonine results when cocaine is taken, but will not be able to say
for certain that there was cocaine in the system at the time of the traffic stop. The evidence
provided by the officers on the scene will be used to convince a judge or jury that the person was under the effect of the drug when stopped.
Ethanol is much easier to work with than illicit drugs. All states have a level of ethanol at
or above which the suspect is deemed to be impaired. Most states use the level of 0.080
g/dL. (Remember that a gram is around 1/28 oz.; a dL or deciliter is 1/10 of a liter, or a
little less than 1/2 cup.) In laymans terms, this means that in every 100 ml (one deciliter)
of blood, there are 0.080 grams or 80 milligrams of ethanol. The amount of alcoholic beverage it takes to get there is dependent on the weight and gender of the individual. There are
several charts available on the internet that provide rough estimates of alcohol concentrations based on weight, gender, and the number of drinks consumed. An example of one
of these charts is shown in Figure 4.1. In these charts one must remember that a drink is
usually defined according to Table 4.1.
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Section 4.4 Toxicology Laboratory Testing
Figure 4.1: Blood alcohol concentration
90 to 109 lbs. 110 to 129 lbs. 130 to 149 lbs. 150 to 169 lbs. 170 to 189 lbs.
190 to
209 lbs.
210 lbs.
and up
Total Drinks
Total Drinks
Total Drinks
Total Drinks
Total Drinks
Total Drinks
Total Drinks
drink 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
1 hr
2 hrs
3 hrs
4 hrs
.01.04% May be DUI Definitely unlawful if under 21 years old
.05%.07% Likely DUI Definitely unlawful if under 21 years old
.08% and up Definitely DUI
As shown in the chart, having one to two drinks can significantly change a persons BAC depending on
his or her weight and the amount of time between each drink. Do you agree that having a BAC of 0.080
g/dL (or .08%) should result in a DUI? Why or why not?
Source: http://www.dmv.ca.gov/pubs/curriculum/Chart%2010%20BAC%20Chart.pdf.
Table 4.1: The amount of alcohol in different drinks
Alcohol concentration
Alcohol present
Normal American
12 ounces
4% or 8 proof
0.48 ounces
6 ounces
8% or 16 proof
0.48 ounces
Mixed drink
1.25 ounces
40% or 80 proof
0.48 ounces
Mixed drink
1 ounce
50% or 100 proof
0.48 ounces
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Section 4.4 Toxicology Laboratory Testing
As you can see, the normal
drink has approximately 1/2
ounce of pure alcohol in it.
However, when people drink,
they often do not have a normal drink. How many times
have you seen offerings at bars
of tall beers that contain 16
or 20 ounces of beer? The same
can happen with mixed drinks
containing higher proof liquors.
People may not actually know
how much alcohol they are putting into their system.
When drinking at bars, people cannot always keep track of
how much they drink, as bartenders do not measure exact
proportions. Do you think they should?
Associated Press
People also do not respond in
the same way to a particular
BAC level. One person may
appear normal at a 0.080 g/dL
level, but another person may
be obviously impaired.
Think About It
Do you know people who become obviously impaired after only one or two drinks? Are there
people you know who seem to be able to drink a lot without appearing impaired at all? Why
do you think this occurs?
This difference in response is called individual variation, and can be due to genetics, previous alcohol use, or a number of other factors. One thing to remember is that even when
people look like they are sober, alcohol is depressing inhibitions and judgment. This
depression is a major cause of accidents. Drivers get into dangerous situations and do
not use good judgment. At higher alcohol levels, the impairment of reflexes and visual
disturbances contribute. If enough alcohol is consumed, a person will pass out, can go
into a coma, and can die. Death can happen due to aspiration, in which a person who has
passed out and lying face up can vomit and then inhale the vomit into the lungs. Death
can also happen due to excessively high alcohol concentrations. The average person dies
at a level of 0.450 g/dL.
Alcohol in the Body
When a person begins drinking, the alcohol is absorbed into the bloodstream and distributed through the body. This is the absorption phase. Once a person stops consuming alcohol, he or she will reach a peak blood alcohol level and then the level will begin
to decrease. The time of this peak is dependent on food intake. If a person drinks on
an empty stomach, the peak is reached in 15 to 30 minutes. If a person has been eating,
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Section 4.4 Toxicology Laboratory Testing
the time to peak absorption can be from 60 to 90 minutes (Baselt, 2011). Regardless, once
the peak alcohol level has been reached, metabolism takes over and the level begins to
decrease. The average metabolic rate for alcohol is 0.015 g/dL/hr. This means that a person who is at a 0.080 g/dL at their peak will be approximately 0.065 g/dL one hour later.
This decrease continues until the alcohol is gone. This is a slight oversimplification, since
metabolism is going on at the same time as absorption, but levels rise as long as intake of
alcohol exceeds metabolism, and levels decrease when metabolism is greater than intake.
Hence, 0.015 g/dL/hr is an average (Baselt, 2011). Some people metabolize more slowly
and some more rapidly, depending on health, genetics, and other factors.
Alcohol is metabolized in the liver. There are two enzymes involved in the process. The
first, alcohol dehydrogenase, converts ethanol to acetaldehyde. The second, aldehyde
dehydrogenase, converts the acetaldehyde to acetic acid. The first enzyme appears to
operate as long as alcohol is present. The second enzyme appears to have various genetically controlled forms that operate differently. Depending on the form a person has inherited from their parents, the acetaldehyde metabolizes at different rates. Some metabolize
the acetaldehyde efficiently while others will metabolize more slowly, allowing acetaldehyde to build up in their system. Since this is genetic, a person may not know how they
will metabolize until they consume ethanol. If they have a slow-functioning aldehyde
dehydrogenase enzyme, they will build up acetaldehyde in their system and experience
the associated flushing and nausea.
There are some calculations that the toxicologist can perform regarding alcohol. As mentioned previously, if serum is used to determine alcohol concentration, the level must be
converted to a whole blood alcohol concentration, because that is the way the impairment
level is written into the law. Another calculation can assist in determining the approximate
BAC at the time of an incident, even when the blood or breathalyzer test is not completed
until hours later. Remember that on average, a person eliminates approximately 0.015
g/dL of ethanol per hour. If the toxicologist knows an alcohol level, and the time difference between the test and an incident, such as an accident or traffic stop, 0.015 g/dL can be
multiplied by the time difference in hours, calculating the amount of ethanol eliminated.
That amount can be added to the level from the test; the result is the approximate level at
the time of the incident. Finally, the toxicologist can estimate the amount of ethanol in a persons system and convert it to an approximate number of drinks in the individuals system.
This can be done if the toxicologist is provided with the persons weight, gender, BAC, and
what the person was drinking. This becomes an issue when the driver states that he or she
only had a couple of drinks, but his or her BAC is exceedingly high. This can be the result
when people forget how much they drank or are not drinking normal drinks.
While the bulk of the forensic toxicologists duties will be related to human performance
and finding drugs or alcohol in submitted samples, there are other aspects to the analysis
performed by these scientists. Drugs can be delivered to victims unknowingly. Some of
these drugs are given by a suspect to render a victim unconscious so they can be sexually
violated. This is often known as drug facilitated sexual assault.
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Section 4.5 Drug Facilitated Sexual Assault
4.5 Drug Facilitated Sexual Assault
nother analysis completed by toxicologists involves the crime of drug facilitated
sexual assault (DFSA). Giving a person a drug for the purposes of rendering him
or her incapable of giving informed consent to sex can result in charges over and
above rape at trial. Most of the drugs used are in the depressant category, and most of
the time alcohol is also involved. When a victim of rape goes to a hospital, the primary
concern is the health and well being of the individual. Samples specifically related to the
assault are collected, but occasionally drugs will not be considered.
As was mentioned briefly in Chapter 1, some nurses receive special training to deal with
sexual assault. These are called sexual assault nurse examiners (SANE). These specially
trained nurses have added knowledge related to sample collection, preservation of the
sample, maintenance of chain of custody, and testimony in court. In areas such as Chicago
and the rest of the state of Illinois, where SANE nurses have been a part of evidence collection in sexual assault cases, prosecution rates have increased because of their expertise (Illinois Attorney General, 2010). Part of their training includes determining whether
drugs have played a part in the crime.
If drugs may be involved, a urine sample is necessary. The urine can be tested for the presence of drugs and alcohol, but no levels will be determined. Because some of the drugs
used are very potent and have short half-lives in the body, such as alprazolam, the sample
must be collected as soon as possible. Additionally, the toxicologist must be made aware
of the nature of the crime as some drugs, such as GHB, need specialized testing. Some
testing may be completed at a hospital, but remember that although hospitals can determine that a depressant is present, they cannot directly identify the drug. For court purposes, the identification of the drug is essential, and since many hospitals do not perform
confirmatory testing, the samples must be sent outside to testing laboratories.
One of the drugs that received
a great deal of press as a date
rape drug was rohypnol, the
standard dosage form of flunitrazepam. This drug was known
on the street as roofies. Flunitrazepam is a potent benzodiazepine that causes sedation,
muscle relaxation, loss of anxiety, and loss of inhibition. This
drug is also known to cause
amnesia in the victim. It accomplishes this so well that another
of the street names for rohypnol
is the forget me drug. Because
of its misuse, the manufacturer
has added a dye to the formulation to make it obvious that
a drug was added to a potential victims drink. Rohypnol is
given in 2 mg dosage forms, so
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Although Rohypnol has never been approved as a legal drug
in the U.S., in other parts of the world, it is a drug available by
prescription used to treat insomnia.
AFP/Getty Images
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Section 4.5 Drug Facilitated Sexual Assault
it is fairly potent; however, it has a half-life of about 20 hours. This means it can be detected
in the urine for about three days. Rohypnol also has a metabolite that can be detected in
the urine, aiding in analysis. This drug has not been approved for use in the United States
by the Food and Drug Administration, so it has always been illegal and unavailable unless
purchased outside the country and brought in surreptitiously.
Other benzodiazepines have been used in DFSA. Benzodiazepines are often used because,
as mentioned in Chapter 3, benzodiazepines react in a synergistic manner with alcohol.
That means the victim given a benzodiazepine-laced beer acts as though he or she had
three to five beers, or had taken three to five doses of benzodiazepine, instead of just two.
The benzodiazepines are found in the urine through normal testing in the toxicology laboratory. The major concern is passage of time between dosing and sample collection. The
more time that passes, the less likely the toxicologist is to find the drug.
Other drugs require more specialized testing. GHB has an extremely short half-life,
between 20 and 60 minutes (Baselt, 2011). This means that four hours after dosing, over
93% of the GHB is metabolized. GHB requires specialized analytical testing not normally
pursued unless specifically requested. Additionally, GHB is a compound found naturally
in the body. Though it is a very low level, it poses a serious problem for the prosecution
of a case. If DFSA is suspected, and the victim arrived at the hospital hours after the incident and urinated before going to the hospital, analysis cannot be completed for GHB, as
nearly all evidence has been eliminated. If GHB is found in this case, but is detected at the
level normally found in humans, the toxicologist could not say the victim was dosed with
the drug. What has been found may just be the naturally occurring level in the person. The
toxicologist can only state that GHB was used in DFSA when the level is higher than that
seen in endogenous levels.
One might ask, if a case is submitted to the toxicology laboratory and is listed as DFSA,
does the toxicologist only look for drugs associated with that crime? The answer is no. The
toxicologist will still examine the sample for all of the drugs as standard procedure, but
will do additional testing for date rape drugs. It is important to find all drugs present in
the urine. This can make some victims uncomfortable, especially if they have engaged in
recreational drug use, such as smoking cannabis. Care must be taken to make victims comfortable and let them know that the recreational use is not of concern to law enforcement.
The toxicologist will not be able to tell the impairment level of the victim during the
assault. Remember, urine is not quantitated for drug levels, since urine levels cannot be
related to impairment levels, so if any information about drug levels is needed, blood
must be tested quantitatively. The toxicologist may be able to provide information on the
effect of drugs alone and in combination with other drugs. However, there will most likely
not be any officer who can testify about impairment, since the victim will most likely not
get to the hospital for hours after the crime takes place. This will make any determination
of behavior at the time of the crime nearly impossible. The importance of the toxicologists
testimony is that the drug was found and the exact identity of it was determined. After
that, the drug must be tied to the suspect and it must be shown that the victim was not taking the drug of his or her own accord. The toxicologist will relay the complete findings of
the analysis. If recreational drugs or alcohol were found in analysis, this will be disclosed.
The toxicologist will not be able to say how the drugs got into the victim, only that they
were present.
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Section 4.6 Forensic Urine Drug Testing
Think About It
Since the SANE program is helping in the judicial process for DFSA cases, do you think that
other medical personnel could receive training to assist in other types of cases? What types of
cases do you think would benefit?
4.6 Forensic Urine Drug Testing
he final topic for discussion in this chapter is forensic urine drug testing (FUDT).
In todays employment climate, most people have probably been drug tested. FUDT
started as employment drug screens. It has spread into the law enforcement world
through testing of urine of probationers and parolees, as well as testing of athletes for
drugs of abuse and performance enhancement. It has even spread into the horse racing
industry, where winners have their urine tested for proscribed drugs. For our purposes,
we will stick to human testing for law enforcement, though this closely mirrors the
employment screening completed on applicants for jobs and those employed where they
are randomly drug tested in the workplace.
Urine drug screens normally
look for what have been referred
to as the NIDA-5, the five classes
of abused drugs checked for in
laboratories as determined by
the National Institute for Drugs
of Abuse (NIDA). These are
amphetamines, opiates, phencyclidine, cocaine, and cannabis.
These were historically the drugs
and drug classes most abused.
Testing begins on samples using
immunoassays. This test is the
same screening test used in the
forensic and medical industries. At first, this was the only
Taking a urine test is something most people have had to do
test done for workplace testat some point in time for a variety of reasons. What are some
ing. Unfortunately, many false
positive results were seen. For
Associated Press example, people who had taken
cough syrup with phenylpropanolamine were listed as positive for amphetamines. The conclusive identification of drugs
eliminated the false positive tests in the amphetamine class. Another problem was seen
with opiates. Reports appeared of people who had submitted urine samples that tested
positive for opiates after they had just eaten something with poppy seeds. Research was
completed, and it was found that if a person consumed enough poppy seeds and gave a
urine sample within several hours of that consumption, it was possible to trigger a positive
test. Guidelines were again set up so that confirmation would take into account the possibility of poppy seed consumption. Today, this is not really a problem.
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Section 4.6 Forensic Urine Drug Testing
While false positives were an issue in the past, safeguards have been instituted that make
false negative results unlikely. A false negative would result when testing indicated there
was no drug present, and in fact there was. Many people have tried to alter their urine
samples so that the drug that might be present would be missed in analysis. These problems have been addressed, as well.
The National Institutes for Drug Abuse (NIDA) was the original agency that licensed testing facilities. It also instituted the guidelines for acceptable testing to avoid false negatives
and false positives from the laboratories doing the FUDT. These included the confirmation
of the identity of drugs found in samples. They also took into account the fact that people
might have passed through rooms where drug use was ongoing but did not participate.
These people might have had passive contact and been exposed to drugs without using
them and could have trace amounts in their system through passive inhalation. Today,
the FUDT laboratories use immunoassay testing to find if drugs might be present, and
the drugs are then confirmed using gas chromatography/mass spectroscopy (GC-MS).
The immunoassay screening tests have cut-off levels for the various classes of drugs to
eliminate the possibility of positive results based on passive inhalation. What this means
is that each drug class has a level greater than zero (no drug present) which would still be
considered negative. If the immunoassay tests indicate levels less than the cut-off value,
the sample is considered negative for drugs and testing is complete. If the sample gives a
reading above the cut-off level, it is considered positive and the sample is isolated for confirmatory testing with GC-MS. This final test will tell which drug is present in the sample.
If, for instance, the drug found is phenylpropanolamine which is a common component in
cold medications, the result will still remain negative. If instead, the drug is methamphetamine, the report will read as positive for that drug.
There are people being tested who have became aware of the procedures being used and
tried to beat the test through adulteration, or the intentional addition of some chemical
for the purposes of interfering with the testing processes, of their urine samples. The goal
of adulteration is to create a false negative test resultin other words, affecting the testing
in some way so that a person who has used drugs will not get caught. Since the testing
only worked with urine at normal levels of acidity and alkalinity in people, those who
were afraid they might give a positive test result would try to alter the pH (acidity) of
their urine. Some would drink vinegar to make it more acidic. Others would add bleach to
their samples to make it alkaline or basic. Other tricks were used to beat the test as well.
Some people substituted drug-free urine for their own urine. They would get a sample of
urine from a friend who did not use drugs, conceal it, try to carry it into the testing facility, and then place it in the sampling cup instead of their own urine. In some facilities this
worked for a while. However, the industry was forced to become more sophisticated in
their methods of testing. Now, the facilities have methods of checking the temperature
of the urine. Urine carried outside the body is too cool and will no longer be accepted.
Another method of trying to beat the test was to take herbs and drink large amounts of
water. This did not eliminate all of the drug, but lowered its concentration so testing indicated levels below the cutoff, resulting in a negative report. Again, a method to detect this
was found. The body creates a compound called creatinine that is excreted in the urine. In
healthy individuals, there is an average concentration range for this compound. Drinking
large amounts of water not only dilutes the drug concentration, but also the creatinine
concentration. This serves as an indicator that diluting and flushing is taking place.
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Section 4.6 Forensic Urine Drug Testing
If it seems like a great deal of time and effort has gone into detecting people trying to
beat the test, there is a reason. Some states have passed legislation mandating that FUDT
laboratories report possible adulteration of urine samples for the purposes of trying to
beat the test. If, for instance, a collector noticed the urine had a very low temperature
when collected, it would be stated on the report. The same would happen if the urine
had a very high or low pH, or if the creatinine level was low and far outside the normal
range. Employers have learned not to look at just the results, but the condition of the urine
sample, noting indicators that someone has tried to beat the system. While the states do
not have a vested interest in the information reported by the laboratories, the employers
gain information about the people they are getting tested.
Forensic toxicology laboratories follow many of the same guidelines for analysis in urine
samples being tested. Many of the cases that require such testing are probation cases.
Many parolees are randomly chosen to give urine samples to prove they are not using
drugs. When this sample comes into a lab, under seal and with complete chain of custody,
the analyst will run preliminary testing for the five classes of abused drugs. If the preliminary testing is negative, the case will be closed and reported as negative. If drugs are
indicated in the preliminary test, then conclusive testing will be completed to identify the
drugs. The report will reflect what drugs were identified.
In spite of the protocols that laboratories have in place, one aspect of testing urine is difficult to catch. In casual users, the drugs of abuse that are being tested for are undetectable in
the urine after 72 to 96 hours have passed, and with some drugs, even less time is needed.
This means that if someone is prepared for the test, he or she can abstain from drug use
for three or four days and will test as drug free. A test developed in the last decade has
expanded the drug detection limits for forensic and employment testing. Techniques have
been developed that allow testing of hair for the presence of drugs. Since nutrients to the
root of the hair are delivered by the blood, drugs in the blood can also be deposited in the
hair. After the drugs are deposited, they will not leave, but are instead trapped until that
section of hair is cut off. This allows the testing laboratory to have a sample with a longer
record of drug use.
Testing facilities have had to develop techniques that can provide information that the
drug came from inside the hair and was not deposited on the outside of the hair, as would
happen with passive contact. Once these techniques were validated, testing could give a
record of drug use much longer than any urine sample. Head hair grows on average about
1 cm, or about a 1/2 inch, per month. A hair sample is collected by cutting hair off next to
the scalp in an amount about the diameter of a pencil. This hair sample can be sectioned
into 1/2 inch pieces. Each section can be tested for drugs. Typically, only the last three
inches, or about six months of growth, will be tested. This will tell the drug history of the
individual for that period of time. Of course people have again tried to beat the test by
shaving their heads, but a drug can be found in any hair. One aspect to hair testing should
be considered with care. This testing cannot tell exactly when a person used drugs; it only
shows that a person took drugs during a month of time as shown in a certain section of
hair. Additionally, there is nothing in this test that indicates impairment due to the drugs.
This testing is much more expensive than urine testing, so if a company uses this type of
testing, they are serious about drugs in the work place.
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Think About It
We have spoken about FUDT, but this type of testing is also used in many other ways. Where
do you think this testing is used outside of forensics?
orensic toxicology is used in a wide variety of casework in forensic science. The testing can determine if a person had drugs in their system, provide a blood alcohol level
that can be used in the determination of DUI cases, and tell if a person died of drug
overdose or was poisoned by a toxic compound. Testing procedures are extensively validated and controls are run on a daily basis to confirm the functioning of the instruments
in the toxicology laboratory. The toxicologist has the tools necessary to assist the case in
the identification of myriad compounds for forensic use and has the knowledge to assist
the courts in the determination of what the effects could possibly have been. As the drugs
become more potent and new designer drugs come on the market, the challenges facing
the toxicologist will keep the exciting field of forensic science continuously growing.
1. Sometimes drugs are converted by the body into other compounds called
a. metabolites
b. poisons
c. enzymes
d. molecules
2. Which of the following is NOT an example of heavy metal poisoning?
a. Arsenic
b. Aluminum
c. Lead
d. Mercury
3. Samples sent to a forensic toxicologist will very often be
a. contained in a special bacteria-protected plastic bag.
b. contained in a DUI or DUID kit.
c. submitted in any plastic container available.
d. dried and sent in a sealed container.
4. Drugs will usually be analyzed
a. by identification in urine, and, if necessary, quantitated in the blood.
b. by identification only in the blood.
c. by identification and quantitation only in the urine.
d. only if vitreous humor is submitted to the laboratory.
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Key Ideas
5. A commonly used drug in drug facilitated sexual assault (DFSA) is
a. phencyclidine.
b. methamphetamine.
c. ethanol.
d. cannabis.
6. The original drugs recommended for testing by the National Institute For Drug
Abuse were called
a. the SAMSHA-10.
b. the NIDA-5.
c. the NIDA-10.
d. controlled substances.
a. metabolites. The answer can be found in Section 4.1.
b. Aluminum. The answer can be found in Section 4.2.
b. contained in a DUI or DUID kit. The answer can be found in Section 4.3.
a. by identification in urine, and, if necessary, quantitated in the blood. The answer can be found in Section 4.4.
c. ethanol. The answer can be found in Section 4.5.
b. the NIDA-5. The answer can be found in Section 4.6.
Key Ideas
Toxicology is the study of the effects of poisons and toxins in the body. Forensic
toxicology applies that information to the courts.
Forensic toxicology can be used in poisonings and human performance cases.
The majority of cases forensic toxicologists deal with are DUI and DUID cases.
Several types of poisons that can be encountered in forensic toxicology cases include
heavy metals, pesticides, carbon monoxide and other gases, drugs, and alcohol.
Chain of custody is important in forensic toxicology cases to make sure the evidence
is admissible in court.
Qualitative testing tells what is in a sample while quantitative testing tells how
much of the substance is present in a sample.
Drug Recognition Experts are police officers trained to assess suspects who may
be under the influence of drugs. Through interviews, testing through the SFST,
and general observation of the suspect, they may be able to ascertain if the suspect is under the influence of depressants, stimulants, hallucinogens, phencyclidine, opiates and narcotics, inhalants, or cannabis.
Preliminary or screening tests tell what class or category of drug may be in a sample; confirmatory tests tell with certainty what drugs are present and the quantity.
Toxicology testing is rigorous and involves the use of positive and negative controls to make sure all testing is functioning properly and quantitative controls to
make sure all quantitative results are accurate.
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Critical Thinking Questions
Drugs generally are prosecuted under per se laws which mean that any amount of
drug in the system indicates impairment, while ethanol relies on certain levels in
the blood or breath to determine impairment by statutory definition.
Drug Facilitated Sexual Assault occurs when a person tries to incapacitate or render a victim unable to make informed decisions about engaging in sex through
the use of drugs.
Forensic Urine Drug Testing has become highly controlled to make sure that correct
results from testing are generated by the testing laboratory and also ensure that
adulteration of samples by the person being tested is detected and reported.
Hair testing is now being used and can increase the detection time of drugs in
people. Care must be taken with the results to make sure no misrepresentation of
the findings occurs.
Critical Thinking Questions
1. Knowing what you know about ethanol and blood alcohol concentration, how
would you explain in court what it means to be driving under the influence, if
you were a toxicologist testifying in a court case about someone driving under
the influence of alcohol and hitting a pedestrian?
2. Arsenic was used in poisonings because it could be misdiagnosed as a disease.
Do you think that a clever poisoner could get away with murder today if they
chose the right poison?
3. The organophosphate pesticides have been seen in accidental poisonings. What
other examples can you think of that use these compounds? What steps do you
think should be taken to prevent accidental poisonings?
4. DRE programs are becoming more prominent in officer training. Do you think this
program should be a requirement to become a police officer? Why or why not?
5. If a person is found dead with many pill bottles around them, does this necessarily
mean they died of a drug overdose? Explain your reasoning.
6. Do you think the DRE will ever take the place of a toxicologist in court? Why or
why not?
7. A person fails their SFST and has a fruity odor on the breath. Could this be anything
other than alcohol intoxication? If so, what?
8. There is a lot of time spent analyzing controls in toxicology. Why do you think all
of these controls are necessary?
9. If the average person can die at a 0.450 g/dL level of ethanol, why are some
samples seen that have higher levels in living people?
10. The SANE nurses can help get good evidence for testing. How is this affected if the
victim waits for two or three days before going into the hospital after an assault?
11. If a person can be shown to have altered their urine to try to get a negative FUDT
result, what do you think should be done?
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Key Terms
Key Terms
acute Immediate, or seen very soon after;
acute tolerance, for example, is seen within
hours of exposure to a compound.
false positive A sample does not contain a
drug, but testing indicates the presence of
that drug.
chronic Something which takes place after
a longer period of time; for example, chronic
dosing means giving a drug for a long
period of time, as opposed to a single dose.
Forensic Urine Drug Testing
(FUDT) Testing that can be used to determine drug use in individuals through the
use of a urine sample, often for parole
cases and employment screens. Testing is
generally for opiates, amphetamines, cannabis, phencyclidine, and cocaine.
adulteration The act of adding a chemical
to a sample for the purposes of interfering with testing by a hospital or forensic
blood draw A sample of blood taken
in order to test for medical or forensic
breathalyzer test Device used to determine the breath alcohol concentration
(BrAC) of a suspect.
carbon monoxide (CO) A highly toxic gas,
usually produced by combustion of hydrocarbon fuels.
confirmatory testing Used to conclusively
identify the particular drug or drugs present after it has been determined that a
particular class of drug might be present.
date rape drug Drug which is used to
render a victim unconscious or incapable
of saying yes or no to sexual intercourse.
Drug Recognition Expert (DRE) A police
officer trained to evaluate suspects and
determine if drugs may be involved in
their behavior.
Drug Facilitated Sexual Assault
(DFSA) The process by which a person
tries to incapacitate or render a victim
unable to make informed decisions about
engaging in sex through the use of drugs.
false negative A sample does contain a
drug, but this drug is not found.
gae80632_04_c04_111-142.indd 140
gases Substances which are vapors naturally or at low temperatures, including CO
and inhalants.
head-space gas chromatography A form
of gas chromatography that uses as the
injected sample air collected from above a
liquid that contains the compound of interest, such as air taken from a sealed vessel
that contained blood suspected of having
alcohol in it.
heavy metals Elements that are toxic
when ingested, such as mercury, lead, arsenic, and thallium.
human performance The ability of a person to complete tasks under various conditions. In toxicology, this usually refers to
impairment caused by ingestion of drugs
or alcohol.
immunoassay tests A class of tests that
relies on a reaction between antigens and
antibodies to produce a result.
internal standard A compound that is not
likely to be found in a sample, which can
be added during analysis to help standardize results for quantitation and identification of a drug.
metabolism The process by which the
body breaks down drugs and other materials to enable their elimination from the
body in the urine or feces.
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Key Terms
metabolite The breakdown product of a
drug once it has been metabolized by the
negative control A standard sample that
does not contain a drug and is used by the
analyst to make sure that the test being
used is working and will show a negative
result when the sample does not contain
the drug being tested for.
NIDA-5 The original five classes of drugs
of abuse which were screened for in urine
drug testing: amphetamines, cocaine,
phencyclidine, cannabinoids, and opiates.
pesticides Compounds used to kill pests,
such as insects, rats, mice, or other similar
poison Any substance capable of causing
death, illness, or harm when taken into the
poisonings The act of ingesting a toxic
substance which can cause bodily harm
or death. This can be accidental or
positive control A standard sample that
does contain a drug and is used by the
analyst to make sure that the test being
used is working and will show a positive
result when the sample does contain the
drug being tested for.
post mortem redistribution Process by
which after death some drugs can move
from a tissue into the blood, or diffuse
from the blood into a tissue. This can cause
unusual values during the determination of the amount of drug in the tissues
or blood. In order to determine if this has
happened, many different samples may be
taken and compared.
gae80632_04_c04_111-142.indd 141
qualitative testing Used to determine
what compounds are in a sample.
quantitative controls A series of dilutions of the compound of interest, which
can be tested to form a chart that assists in
determining the amount of compound in a
quantitative testing Used to determine
the amount of a compound in a sample.
serum The fluid remaining when blood
is allowed to clot and the clot is then
Sexual Assault Nurse Examiners
(SANE) Nurses specially trained to help
collect and preserve evidence in sexual
assault cases.
Standardized Field Sobriety Test
(SFST) Testing given to a suspect thought
to be under the influence of drugs or alcohol, consisting of the walk and turn, finger
to nose, and one leg stand tests.
testing of hair In forensic toxicology,
determining the presence of drugs, drug
metabolites, or toxins in a persons hair.
toxicology Study of poisons and toxins in
the body.
urine sample A specimen of urine known
to have come from a particular person.
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Web Resources
Web Resources
The NIDA website:
A sample BAC calculator:
Audio news story on the history of toxicology:
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What are the three standardized tests used by officers to determine if a suspect is impaired?
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Driving under the influence of alcohol is a serious offense that can have severe consequences. To determine if a motorist is impaired, law enforcement officers use Field Sobriety Tests (FSTs) to determine if a motorist is under the influence of drugs or alcohol. This assignment provides students with an opportunity to conduct their own mock FSTs, evaluate their ability to perform the tests and any issues related to these tests.


In this assignment, students can select one of the learning activities provided to conduct mock FSTs using the three standardized tests outlined in the text. Then, they can document their findings in a two-page paper formatted according to the APA style.

The students should describe the three field sobriety tests included in the assignment, explain their ability to conduct the tests, and evaluate field sobriety tests as a persuasive means of proving impairment by alcohol. Additionally, the paper should discuss the weaknesses of using field sobriety tests in court to prove alcohol impairment.

Finally, students should explain what it means to be driving under the influence of alcohol using their knowledge of ethanol and blood alcohol concentration. They should cite their resources in text and on the Reference page, as appropriate, following the guidelines provided by the Ashford Writing Center.

1. To conduct a Field Sobriety Test (FST) and evaluate the ability to perform the test.
2. To understand the relationship between ethanol and blood alcohol concentration in determining if someone is driving under the influence.
3. To document findings in a two-page paper using APA style.

Learning Outcomes:
By the end of this assignment, learners should be able to:
1. Conduct a mock FST using the three standardized tests and evaluate the ability to perform the tests.
2. Explain what it means to be driving under the influence by understanding the relationship between ethanol and blood alcohol concentration.
3. Describe the field sobriety tests, evaluate field sobriety tests as a persuasive means of proving impairment by alcohol, and explain the weaknesses of using field sobriety tests in court to prove alcohol impairment.
4. Use APA style to format the assignment and cite resources in text and on the Reference page.

Heading: Forensic Toxicology

1. To identify the different types of cases that toxicologists analyze.
2. To describe different poisons and how they are sampled.
3. To explain how officers recognize drugs and alcohol in the field and how samples are obtained for toxicologists.
4. To discuss how toxicologists test blood and urine samples for drugs and alcohol.
5. To describe the drugs used in drug-facilitated sexual assault and how they are analyzed.
6. To explain the purpose of forensic urine drug testing and how it is done.

Learning Outcomes:
By the end of this chapter, learners should be able to:
1. Identify the different types of cases that toxicologists analyze, such as poisoning, drug overdose, and DUI cases.
2. Explain the methods used to sample different poisons and drugs for analysis, including hair, saliva, and blood samples.
3. Describe how officers recognize drugs and alcohol in the field and the methods used to obtain samples for toxicologists, such as breathalyzers and blood tests.
4. Explain the methods used by toxicologists to test blood and urine samples for drugs and alcohol, including gas chromatography-mass spectrometry (GC-MS) and enzyme multiplied immunoassay technique (EMIT).
5. Describe the different types of drugs used in drug-facilitated sexual assault and how they are analyzed, including gamma-hydroxybutyric acid (GHB) and ketamine.
6. Explain the purpose of forensic urine drug testing and how it is done, including the types of drugs detected and the limitations of the test.

Solution 1: Conducting Your Own Field Sobriety Test

Field Sobriety Tests are a widely used method by officers to determine if a suspect is impaired. In this solution, you will get the opportunity to conduct your own tests and evaluate their effectiveness.

Firstly, you need to choose one of the three standardized tests and conduct mock FSTs. This will give you a firsthand experience of the tests and allow you to evaluate your ability to perform them. As you conduct these tests, make notes of any issues you feel these tests might provide. These notes will help you in understanding the weaknesses of using field sobriety tests in court to prove alcohol impairment.

Now that you have conducted the tests, it’s time to document your findings in a two-page paper. Start with a brief detailing of each of the field sobriety tests, followed by your evaluation of your ability to perform them. Then, evaluate field sobriety tests as a persuasive means of proving impairment by alcohol. Finally, explain the weaknesses and limitations of using field sobriety tests in court to prove alcohol impairment.

Solution 2: Evaluating Field Sobriety Tests in a Video

In this solution, you will watch a video of an officer initiating a traffic stop of a suspected drunk driver and the officer’s attempted evaluation of the driver. You will document the manner in which she performed these tests and evaluate their effectiveness.

After watching the video, write a two-page paper. Start with a brief detailing of the field sobriety tests used by the officer in the video. Describe the ability of the driver to perform the tests assigned and evaluate the field sobriety tests as a persuasive means of proving impairment by alcohol.

Now, explain how ethanol and blood alcohol concentration are linked and how they determine the level of alcohol impairment. This will help you in explaining to the court what it means to be driving under the influence. Finally, explain the weaknesses of using field sobriety tests in court to prove alcohol impairment.

Remember to format your paper in APA style and cite your resources in text and on the Reference page, as appropriate. The Ashford Writing Center has plenty of APA samples and tutorials to assist you in this.

Suggested Resources/Books:

1. “Field Sobriety Testing: How to Conduct and Defend Sobriety Tests” by Steven Oberman and Lawrence Taylor
2. “Drunk Driving Defense, Seventh Edition” by Lawrence Taylor and Steven Oberman
3. “Forensic Toxicology: Principles and Concepts” by Nicholas H. Proctor and Associates
4. “Alcohols and Toxicology” by Timothy S. Tracy and Randall C. Baselt

Similar asked questions:

1. What are the three standardized tests used by an officer to determine if a suspect is impaired?
2. What are the weaknesses of using field sobriety tests in court to prove alcohol impairment?
3. How do officers recognize drugs and alcohol in the field and how do they obtain samples for the toxicologist?
4. What are the different poisons that toxicologists analyze?
5. What is drug-facilitated sexual assault, and how are the drugs analyzed?

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Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

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Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

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Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

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Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

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Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

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