DWI Detection and Standardized Field Sobriety Testing
March 2013 Edition
HS 178 R5/13 23 of 24
The force exerted by blood on the walls of the arteries. Blood pressure changes continuously, as the heart cycles between contraction and expansion.
Abnormally slow heart rate; pulse rate below the normal range.
Abnormally slow rate of breathing.
Grinding the teeth. This behavior is often seen in person who are under the
influence of cocaine or other CNS Stimulants.
This is the drug category that includes marijuana. Marijuana comes primarily from the leaves of certain species of Cannabis plants that grow readily all over the temperate zones of the earth. Hashish is another drug in this category, and is made from dried and pressed resin of a marijuana plant. The active ingredient in both Marijuana and Hashish is a chemical called delta-9 tetrahydrocannabinol, usually abbreviated THC.
This is the drug category that includes Mari
A metabolite of THC (tetrahydrocannabinol).
Abnormal pattern of breathing. Marked by breathlessness and deep, fast breathing.
CLUE -Something that leads to the solution of a problem.
CNS (Central Nervous System) A system within the body consisting of the brain, the brain stem, and the spinal cord.
One of the seven drug categories. CNS Depressants include alcohol,
barbiturates, anti-anxiety tranquilizers, and numerous other drugs.
One of the seven drug categories. CNS Stimulants include Cocaine, the
Amphetamines, Ritalin, Preludin, and numerous other drugs.
HS 178 R5/13 10 of 24
An inflammation of the mucous membrane that lines the inner surface of the eyelids caused by infection, allergy, or outside factors. May be bacterial or viral. Persons suffering from conjunctivitis may show symptoms in one eye only. This condition is commonly referred to as "pink eye", a condition that could be mistaken for the bloodshot eyes produced by alcohol or Cannabis.
The "crossing" of the eyes that occurs when a person is able to focus on a stimulus as it is pushed slowly toward the bridge of their nose. (See, also, "Lack of Convergence".)
Cocaine base, appears as a hard chunk form resembling pebbles or small rocks. It produces a very intense, but relatively short duration "high".
CUE -A reminder or prompting as a signal to do something. A suggestion or a hint.
A written summary of a person's education, training, experience, noteworthy
achievements and other relevant information about a particular topic.
A manifestation of impairment due to certain drugs, in which the suspect alternates between periods (or cycles) of intense agitation and relative calm. Cyclic behavior, for example, sometimes will be observed in persons under the influence of PCP.
A brief state characterized by incoherent excitement, confused speech,
restlessness, and possible hallucinations.
The part of a neuron (nerve cell) that receives a neurotransmitter.
The chemical name for Heroin.
The lowest value of blood pressure. The blood pressure reaches its diastolic value when the heart is fully expanded, or relaxed (Diastole).
HS 178 R5/13 11 of 24
One of the seven drug categories. Includes drugs that inhibits pain by cutting off or disassociating the brain's perception of pain. PCP and its analogs are considered Dissociative Anesthetics.
Concentrating on more than one thing at a time. The four psychophysical tests used by DREs require the suspect to divide attention.
DIVIDED ATTENTION TEST
A test which requires the subject to concentrate on both mental and physical tasks at the same time.
An effect that may occur when the body reacts to the presence of a drug by producing hormones or neurotransmitters to counteract the effects of the drug consumed.
Any substance that, when taken into the human body, can impair the ability of the person to operate a vehicle safely.
The acronym "DWI" means driving while impaired and is synonymous with the acronym "DUI", driving under the influence or other acronyms used to denote impaired driving. These terms refer to any and all offenses involving the operation of vehicles by persons under the influence of alcohol and/or other drugs.
DWI DETECTION PROCESS
The entire process of identifying and gathering evidence to determine whether or not a subject should be arrested for a DWI violation. The DWI detection process has three phases:
1. Phase One -Vehicle In Motion
2. Phase Two -Personal Contact
3. Phase Three -Pre-arrest Screening
DYSARTHIA Slurred speech. Difficult, poorly articulated speech.
DYSPNEA et. al. Shortness of breath.
HS 178 R5/13 12 of 24
An abnormal condition that prevents the affected person from properly estimating distances linked to muscular movements.
A disorder of mood. Feelings of depression and anguish.
See: "Motor Nerves".
The network of glands that do not have ducts and other structures. They secrete hormones into the blood stream to affect a number of functions in the body.
Any means by which some alleged fact that has been submitted to investigation may either be established or disproved. Evidence of a DWI violation may be of various types:
- • Physical (or real) evidence: something tangible, visible, or audible.
- • Well established facts (judicial notice).
- • Demonstrative evidence: demonstrations performed in the courtroom.
- • Written matter or documentation.
- • Testimony.
A person skilled in some art, trade, science or profession, having knowledge of matters not within knowledge of persons of average education, learning and experience, may assist a jury in arriving at a verdict by expressing an opinion on a state of facts shown by the evidence and based upon his or her special knowledge. (NOTE: Only the court can determine whether a witness is qualified to testify as an expert.)
FIELD SOBRIETY TEST
Any one of several roadside tests that can be used to determine whether a subject is impaired.
A vivid recollection of a portion of an hallucinogenic experience. Essentially, it is a very intense daydream. There are three types: (1) emotional --feelings of panic, fear, etc.; (2) somatic --altered body sensations, tremors, dizziness, etc.; and (3) perceptual --distortions of vision, hearing, smell, etc.
HS 178 R5/13 13 of 24
Chatter, rambling or pointless speech. Talkative.
A sensory experience of something that does not exist outside the mind, e.g., seeing, hearing, smelling, or feeling something that isn't really there. Also, having a distorted sensory perception, so that things appear differently than they are.
One of the seven drug categories. Hallucinogens include LSD, MDMA, Peyote, Psilocybin, and numerous other drugs.
A form of cannabis made from the dried and pressed resin of a marijuana plant.
Sometimes referred to as “marijuana oil” it is a highly concentrated syrup-like oil extracted from marijuana. It is normally produced by soaking marijuana in a container of solvent, such as acetone or alcohol for several hours and after the solvent has evaporated, a thick syrup-like oil is produced with a higher THC content.
A powerful and widely-abused narcotic analgesic that is chemically derived from morphine. The chemical, or generic name of heroin is "diacetyl morphine".
A rhythmic change in the pupil size of the eyes, as they dilate and constrict when observed in darkness independent of changes in light intensity, accommodation (focusing), or other forms of sensory stimulation. Normally only observed with specialized equipment.
The dynamic balance, or steady state, involving levels of salts, water, sugars, and other materials in the body's fluids.
HORIZONTAL GAZE NYSTAGMUS (HGN)
Involuntary jerking of the eyes occurring as the eyes gaze to the side. The first test administered in the SFST battery.
HS 178 R5/13 14 of 24
Chemicals produced by the body's endocrine system that are carried through the blood stream to the target organ. They exert great influence on the growth and development of the individual, and that aid in the regulation of numerous body processes.
A metabolite of THC (tetrahydrocannabinol).
Exaggerated or over extended motions.
Excess sugar in the blood.
A deep, rapid or labored breathing.
Extremely high body temperature.
A neurological condition marked by increased reflex reactions.
Abnormally high blood pressure. Do not confuse this with hypotension.
An abnormal decrease of blood sugar levels.
Shallow or slow breathing.
Abnormally low blood pressure. Do not confuse this with hypertension.
Decreased body temperature.
A crystalline form of methamphetamine that produces a very intense and fairly long-lasting "high".
ILLEGAL PER SE
Unlawful in and of itself. Used to describe a law which makes it illegal to drive while having a statutorily prohibited Blood Alcohol Concentration.
HS 178 R5/13 15 of 24
One of the seven drug categories. The inhalants include volatile solvents (such as glue and gasoline), aerosols (such as hair spray and insecticides) and anesthetic gases (such as nitrous oxide).
The skin and accessory structures, hair and nails. Functions include protection, maintenance of body temperature, excretion of waste, and sensory perceptions.
"Within the eyeball".
A series of distinct sounds produced by blood passing through an artery, as the external pressure on the artery drops from the systolic value to the diastolic value.
LACK OF CONVERGENCE
The inability of a person's eyes to converge, or "cross" as the person attempts to focus on a stimulus as it is pushed slowly toward the bridge of his or her nose.
Common term for the Cannabis Sativa plant. Usually refers to the dried leaves of the plant. This is the most common form of the cannabis category.
A drug containing a synthetic form of THC (tetrahydrocannabinol). Marinol belongs to the cannabis category of drugs, but marinol is not produced from any species of cannabis plant.
The sum of all chemical processes that take place in the body as they relate to the movements of nutrients in the blood after digestion, resulting in growth, energy, release of wastes, and other body functions. The process by which the body, using oxygen, enzymes and other internal chemicals, breaks down ingested substances such as food and drugs so they may be consumed and eliminated. Metabolism takes place in two phases. The first step is the constructive phase (anabolism) where smaller molecules are converted to larger molecules. The second steps is the destructive phase (catabolism) where large molecules are broken down into smaller molecules.
HS 178 R5/13 16 of 24
A chemical product, formed by the reaction of a drug with oxygen and/or other substances in the body.
Abnormally constricted pupils.
Nerves that carry messages away from the brain, to be body's muscles, tissues, and organs. Motor nerves are also known as efferent nerves.
Rigid muscle tone.
Abnormally dilated pupils.
One of the seven drug categories. Narcotic analgesics include opium, the natural alkaloids of opium (such as morphine, codeine and thebaine), the derivatives of opium (such as heroin, dilaudid, oxycodone and percodan), and the synthetic narcotics (such as demerol and numorphan).
A cord-like fiber that carries messages either to or from the brain. For drug evaluation and classification purposes, a nerve can be pictured as a series of "wire-like" segments, with small spaces or gaps between the segments.
A nerve cell. The basic functional unit of a nerve. It contains a nucleus within a cell body with one or more axons and dendrites.
Chemicals that pass from the axon of one nerve cell to the dendrite of the next cell, and that carry messages across the gap between the two nerve cells.
One mechanism of polydrug interaction. For a particular indicator of impairment, two drugs produce a null effect if neither of them affects that indicator. For example, PCP does not affect pupil size, and alcohol does not affect pupil size. The combination of PCP and alcohol produces a null effect on pupil size.
HS 178 R5/13 17 of 24
An involuntary jerking of the eyes.
ONE LEG STAND (OLS)
A divided attention field sobriety test. The third test administered in the SFST battery.
"ON THE NOD"
A semi-conscious state of deep relaxation. Typically induced by impairment due to Heroin or other narcotic analgesic. The suspect's eyelids droop, and chin rests on the chest. Suspect may appear to be asleep, but can be easily aroused and will respond to questions.
One mechanism of polydrug interaction. For a particular indicator of impairment, two drugs produce an overlapping effect if one of them affects the indicator but the other doesn't. For example, cocaine dilates pupils while alcohol doesn't affect pupil size. The combination of cocaine and alcohol produces an overlapping effect on pupil size: the combination will cause the pupils to dilate.
An abnormal paleness or lack of color in the skin.
Mental disorder characterized delusions and the projection of personal conflicts, that are ascribed to the supposed hostility of others.
Drug paraphernalia are the various kinds of tools and other equipment used to store, transport or ingest a drug. Hypodermic needles, small pipes, bent spoons, etc., are examples of drug paraphernalia. The singular form of the word is "paraphernalium". For example, one hypodermic needle would be called a "drug paraphernalium".
An autonomic nerve that commands the body to relax and to carry out tranquil activities. The brain uses parasympathetic nerves to send "at ease" commands to the muscles, tissues, and organs.
Drugs that mimic neurotransmitter associated with the parasympathetic nerves. These drugs artificially cause the transmission of messages that produce lower blood pressure, drowsiness, etc.
HS 178 R5/13 18 of 24
PDR (Physician's Desk Reference)
A basic reference source for drug recognition experts. The PDR provides detailed information on the physical appearance and psychoactive effects of licitly-manufactured drugs.
The second phase in the DWI detection process. In this phase the officer observes and interviews the driver face to face; determines whether to ask the driver to step from the vehicle; and observes the driver's exit and walk from the vehicle.
A contraction of PHENYL CYCLOHEXYL PIPERIDINE, or PCP. Formerly used as a surgical anesthetic, however, it has no current legitimate medical use in humans.
PHENYL CYCLOHEXYL PIPERIDINE (PCP)
Often called "phencyclidine" or “PCP”, it is a specific drug belonging to the Dissociative Anesthetics category.
Physiology is the branch of biology dealing with the functions and activities of life or living matter and the physical and chemical phenomena involved.
Literally, "hair standing up", or goose bumps. This condition of the skin is often observed in persons who are under the influence of LSD.
POLY DRUG USE
Ingesting drugs from two or more drug categories.
The third phase in the DWI detection process. In this phase the officer administers field sobriety tests to determine whether there is probable cause to arrest the driver for DWI, and administers or arranges for a preliminary breath test.
PRELIMINARY BREATH TEST (PBT)
A pre-arrest breath test administered during investigation of a possible DWI violator to obtain an indication of the person's blood alcohol concentration.
HS 178 R5/13 19 of 24
It is more than mere suspicion; facts and circumstances within the officer’s knowledge, and of which he or she has reasonably trustworthy information, are sufficient to warrant a person of reasonable caution to believe that an offense has been or is being committed.
A mental state characterized by a profound sense of intensified or altered sensory perception sometimes accompanied by hallucinations.
Methods of investigating the mental (psycho-) and physical characteristics of a person suspected of alcohol or drug impairment. Most psychophysical tests employ the concept of divided attention to assess a suspect's impairment.
Literally, "creating psychosis" or "giving birth to insanity". A drug is considered to be psychotogenic if persons who are under the influence of the drug become insane, and remain so after the drug wears off.
Literally, "mimicking psychosis" or "impersonating insanity". A drug is considered to be psychotomimetic if persons who are under the influence of the drug look and act insane while they are under the influence.
The expansion and relaxation of the walls of an artery, caused by the surging flow of blood.
The number of expansions of an artery per minute.
PUPILLARY LIGHT REFLEX
The pupils of the eyes will constrict and dilate depending on changes in lighting.
The continuous, irregular change in the size of the pupils that may be observed under room or steady light conditions.
HS 178 R5/13 20 of 24
Less than probable cause but more than mere suspicion; exists when an officer, in light of his or her training and experience, reasonably believes and can articulate that criminal activity is taking, has taken or is about to take place.
A period of pupillary constriction followed by a period of pupillary dilation where the pupil steadily increases in size and does not return to its original constricted size.
Jerking of the eyes as they look straight ahead.
A dense white fibrous membrane that, with the cornea, forms the external covering of the eyeball (i.e., the white part of the eye).
Nerves that carry messages to the brain, from the various parts of the body, including notably the sense organs(eyes, ears, etc.). Sensory nerves are also known as afferent nerves.
The unpollenated female cannabis plant, having a relatively high concentration of THC.
STANDARDIZED FIELD SOBRIETY TESTING (SFST)
Standardized Field Sobriety Testing. There are three SFSTs, namely Horizontal Gaze Nystagmus (HGN), Walk and Turn, and One Leg Stand. Based on a series of controlled laboratory studies, scientifically validated clues of alcohol impairment have been identified for each of these three tests. They are the only Standardized Field Sobriety Tests for which validated clues have been identified.
One method of ingesting certain drugs. Snorting requires that the drug be in powdered form. The user rapidly draws the drug up into the nostril, usually via a paper or glass tube. Snorting is also known as insufflation.
A medical device used to measure blood pressure. It consists of an arm or leg cuff with an air bag attached to a tube and a bulb for pumping air into the bag, and a gauge for showing the amount of air pressure being pressed against the artery.
HS 178 R5/13 21 of 24
A medical instrument used, for drug evaluation and classification purposes, to listen to the sounds produced by blood passing through an artery.
An autonomic nerve that commands the body to react in response to excitement, stress, fear, etc. The brain uses sympathetic nerves to send "wake up calls" and "fire alarms" to the muscles, tissues and organs.
Drugs that mimic the neurotransmitter associated with the sympathetic nerves. These drugs artificially cause the transmission of messages that produce elevated blood pressure, dilated pupils, etc.
SYNAPSE (or Synaptic Gap)
The gap or space between two neurons (nerve cells).
A sensory perception disorder, in which an input via one sense is perceived by the brain as an input via another sense. In its simplest terms, it is a transposition of senses. For example, seeing a particular sight may cause the user to perceive a sound.
The highest value of blood pressure. The blood pressure reaches its systolic value when the heart is fully contracted (systole), and blood is sent surging into the arteries.
Abnormally rapid heart rate; pulse rate above the normal range.
Abnormally rapid rate of breathing.
THC (Tetrahydrocannabinol) The principal psychoactive ingredient in drugs belonging to the cannabis category.
Breath from the upper part of the lungs and mouth.
HS 178 R5/13 22 of 24
An adjustment of the drug user's body and brain to the repeated presence of the drug. As tolerance develops, the user will experience diminishing psychoactive effects from the same dose of the drug. As a result, the user typically will steadily increase the dose he or she takes, in an effort to achieve the same psychoactive effect.
Scar tissue usually produced by repeated injection of drugs, via hypodermic needle, along a segment of a vein.
TRAFFIC SAFETY RESOURCE PROSECUTOR (TSRP)
Is usually a current or former prosecutor who provides training, education and technical support to traffic crimes prosecutors and law enforcement agencies throughout their state. For the contact information of your TSRP go to:
Conforming to accepted principles. Producing accurate and reliable results.
A documented act of demonstrating that a procedure, process, and/or activity will consistently lead to accurate and reliable results.
VEHICLE IN MOTION
The first phase in the DWI detection process. In this phase the officer observes the vehicle in operation, determines whether to stop the vehicle, and observes the stopping sequence.
VERTICAL GAZE NYSTAGMUS
An involuntary jerking of the eyes (up-and-down) which occurs as the eyes are held at maximum elevation. The jerking should be distinct and sustained.
A French expression literally meaning “to see, to say.” Loosely, this would be rendered in English as “To seek the truth,” or “to call it as you see it.” In a law or court context, one application of voir dire is to question a witness to assess his or her qualifications to be considered an expert in some matter pending before the court.
A motor nerve that carries messages to a muscle that we consciously control.
HS 178 R5/13 23 of 24