“The drug recognition expert procedure is a systematic and standardized method of examining a suspect to determine: 1) Whether the suspect is impaired; and if so, 2) Whether the impairment related to drugs or medical condition; and if drugs, 3) The category or combination of categories of drugs that are the likely cause of impairment” (IV-3, HS 172A R01/10). “It is a systematic process because it is based on a complete set of observable signs and symptoms that are known to be reliable indicators of drug impairment. A Drug Recognition Expert (DRE) never reaches a conclusion based on any one element of the evaluation, but instead on the totality of facts that emerge” (IV-3, HS 172A R01/10). “The evaluation is standardized because DRE officers perform it the same way every time. By conducting a standardized and systematic evaluation, you will help avoid mistakes and help promote and maintain professionalism and consistency among DREs. (IV-3, HS 172A R01/10) “The systematic and standardized evaluation is broken down into twelve major components or steps. The checklist lists the twelve components in the sequence in which they must be performed. DREs refer to the checklist every time they conduct an examination” (IV-3, HS 172A R01/10).
Step one of the Drug Evaluation and Classification (DEC) evaluation is to obtain an accurate measurement of the alcohol concentration in the evaluated person’s blood. The breath test is conducted to rule out alcohol as the contributing agent responsible for the intoxication. Since the DEC practitioner’s job is to identify drugs other than alcohol as the impairing substance, the breath test must be conducted to rule alcohol out as the source of intoxication.
Step two of the DEC evaluation is to interview the arresting officer. It is at this point in the evaluation that the DRE uncovers information that occurred prior to his/her involvement with the case. The DRE must take some time to discuss with the arresting officer relevant driving facts, individual reactions to the stop command, the individual’s demeanor when contacted, unusual odors or statements made, poor physical abilities, appearances, and paraphernalia or dugs found at the scene or in the individual’s possession. It is through this interaction that valuable pre-assessment information in collected and insight into possible drug use or categories of drug use can be considered.
The preliminary examination is a structured series of questions, specific observations, and simple test that provide the first opportunity to examine the suspect closely and directly. One major purpose of the preliminary examination is to determine if the suspect may be suffering from an injury or some other condition not necessarily related to drugs. Another major purpose of the preliminary examination is to begin systematically assessing the suspect’s appearance, behavior, etc. for signs of possible drug influence. The preliminary examination also provides the evaluator with an opportunity to observe the suspects face, breath and speech; the initial check of the eyes; and the first of three pulse rate checks.
The eye exams consist of three tests, namely the Horizontal Gaze Nystagmus (HGN) test, the Vertical Gaze Nystagmus (VGN) test, and Lack of Convergence (LOC) test.
Four separate divided attention tests are administered in this segment of the drug influence evaluation. The following tests are administered in this order: Romberg balance, Walk-and-Turn, One-Leg Stand, and Finger to Nose.
In this test, the DRE tells the person to stand straight with their hells together and their arms at their sides and to maintain that position while instructions are provided. The DRE then asks the individual if they understand. The DRE tells the individual to tilt their head slightly back, close their eyes, stand perfectly straight, and estimate the passing of 30 seconds. When the individual believes that 30 seconds has lapsed, they tilt their head forward, open their eyes, and say stop.
The Romberg balance test is intended to assess a person’s ability to estimate passing time using what is commonly referred to as the internal clock. The internal clock is simply how a person perceives time in their mind in relation to the actual passage of time. With persons who use different types of drugs, the internal clock may speed up, slow down, or remain normal. The category of drug the person is under the influence of determines how their internal clock will behave. For instance, if a person is under the influence of a stimulant category of drug (amphetamines), the internal clock in most cases would speed up due to the psychoactive properties of the drug in the system. In comparison, if a person is under the influence of a depressant category drug (Soma), then the internal clock may be slow.
The Walk-and-Turn test is administered in two stages: the instructional stage and the walking stage. In the instructional stage, the tested person is instructed to imagine a line extending from their left foot straight out in front of them. The individual is told to place their left food on the imaginary line and then place their right food in front of the left, touching the heel of the right foot against the toe of the left. The tested individual is told to keep their arms down to their sides and to remain standing in this position until told to start the test. The tested individual is told not to begin the test until instructed to do so then ask if they understand the instructions up to that point. The tested individual is required to stand in this position and the intent is to measure the ability to follow and retain information from the instructions given to assess physical abilities such as balance.
Once the tested individual understands, the DRE continues with the instructions for the walking stage of the test. The DRE informs the tested individual that when instructed to begin, they need to walk a straight line, taking a series of nine heel-to-toe steps on the imaginary line. While taking those steps the tested individual must keep their arms to their sides, look down at their feet, count each step taken aloud, and touch each step in a heel-to-toe manner. Upon reaching the night step, they are to turn around by keeping the lead foot on the line and taking a series of short steps around then return back down the line taking nine heel-to-toe steps along the imaginary straight line. Lastly, the tested individual is told that once they begin the test they are not to stop walking until they complete the test. After giving all of these instructions, the administering DRE asks the individual if they understand the information provided to them. If the tested individual understands the instructions, they are told to begin the test and count their first step forward from the heel to toe position as one. While walking, the tested individual is assessed for their ability to divide their attention between physical actions such as walking the line and mental abilities such as short-term memory recall and number processing.
The third divided attention sobriety test administered in this portion of the DEC evaluation is the One-Leg Stand test. As is with the Walk-and-Turn test, the one leg stand test is administered in two separate stages: the instructional stage and the balance and counting stage. In the instructional stage, the individual is told to place their feet together side by side, keep their arms down to the side, and remain in that position until instructed to begin the test. The individual is told not to begin the test until instructed to do so and then asked if they understand the instructions up to that point. The individual is required to stand in this position, and the intent is to measure the ability to follow and retain information from the instructions given and to assess physical abilities such as balance.
Once the tested individual understands, the DRE continues with the instructions for the balance and counting stage of the test. The DRE informs the individual that when instructed to begin, they will raise their right leg up into the air approximately 6 inches off the ground while keeping both legs straight and their arms to their sides. The individual is told to point the toe of the elevated foot down and to look at the raised foot while counting in 1000s until told to stop. The administrating evaluator times the test for 30 seconds. The intent of the balance and counting stage of the test is to measure the individual’s ability to follow and retain information form the instruction given and to assess physical abilities such as balance. Once the individual’s ability to balance while holding up his/her leg is complete, the process is repeated assessing his/her balance holding up the left leg.
In this assessment, the tested individual is required to bring the tip of their index finger up to touch the tip of their nose. The individual performs this test with their eyes closed and their head tilted back slightly. The individual stands with their feet together side by side. Once in this position, the individual attempts to touch the tip of the nose with their index finger six times, three times with each hand. The DRE instructs the individual which hand to use for each attempt. The DRE uses the same sequence when administering this test: left, right, left, right, right, left.
The next test of the DEC evaluation is to conduct and assessment of the individual’s vital signs, which includes systematic checks of blood pressure, pulse rate, and body temperature. Since certain categories of drugs affect human physiology differently, indicators of possible impairment may be assessed in this stage of the evaluation. For example, drugs that fall into the categories of stimulants, hallucinogens, and PCP may cause an individual’s pulse rate, temperature, and blood pressure to be elevated. Other drug categories such as narcotic analgesics may cause an individual’s pulse, blood pressure, and body temperature to be lower than normal. Depending on the types of drugs taken and whether they are active in the body, different physiological manifestation could be observed. This is why it is very important for DRE to assess vital signs in the DEC evaluation.
The pulse rate is measured by covering the radical pulse point located on the inside of the wrist closest to the thumb. The DRE covers the pulse point with his or her index and middle fingers, then counts the number of beats felt within a 30-second time period. Two to get the range of pulse beats per minute, then multiplies this number. The normal pulse rate range is between 60 and 90 beats per minute. Readings less than 60 beats per minute are considered down, while anything about 90 beats per minute is considered up/elevated.
Blood pressure is appraised by wrapping the upper portion of the arm (bicep) with the pressure cuff and inflating the cuff so that no blood moves through the artery. Slowly, the pressure inside the cuff is released so that some of the blood begins spurting through the artery. When the blood rushing through the artery is clearly audible and clear tapping sound is heard, the systolic pressure value is recorded. As more pressure inside of cuff is released, a swishing sound should be discernable. The faint tapping at the end of this swishing is the diastolic pressure value.
Blood pressure is assessed by checking for more normal range of systolic and diastolic pressure levels. The systolic pressure is a measure of heart contraction, which sends blood rushing into the arteries. Normal systolic pressure is between 120 and 140 millimeters of mercury (mmHg). Diastolic pressure is a measure of pressure when the heart is fully expanded. The normal range for diastolic pressure is between 70 and 90 mmHg.
To properly measure body temperature, an electronic thermometer is used to obtain an oral reading. A disposable sheath covers the thermometer prior to placing it into the mouth and under the tongue. The normal range of body temperature is 98.6ºF ± 1ºF.
As with the pulse rate and blood pressure, different categories of drugs can cause the body to rise, lower, or maintain body temperature. For instance, depressant category drugs usually do not affect body temperature. On the other hand, narcotic analgesics and some inhalants may cause lowered body temperature, while stimulants, hallucinogens, and PCP usually elevate body temperature.
The principle activity during the dark room examination is the estimation of the size of the subject’s pupils in three different lighting conditions (room light, near total darkness, and direct light). Two other activities also take place in the dark room examination. A check of the subject’s oral cavity and nasal passages are conducted to assess possible methods of drug ingestion and for possible trace elements of drugs themselves.
According to NHTSA DECP curriculum the normal pupillary size ranges vary depending on the lighting condition tested under. For room light normal ranges from 2.5 to 5.0 mm. darkness is from 5.0 to 8.5 mm, and direct light ranges from 2.0 to 4.5 mm. Each assessment of the eye for size should be evaluated using a pupilometer that has several size dots on it in millimeters. The pupilometer is placed to the side of the person’s face and the dots on the card are measured to the actual size of the pupil.
Upon completing the dark room examination, the DRE has the individual sit down and place their arms on a table. The DRE then places their hands on the arms of the individual, checking for normal, rigid, or flaccid muscle tone. The DRE always begins checking the individual’s muscle tone using the left arm. The upper arm is checked first and the hands are worked down the length of the arm to determine the tone of the muscle.
This examination is conducted because different categories of drugs may cause the muscles of the body to react in a manner other than normal. Examples of drug categories that might possibly cause the muscles to become rigid are PCP, hallucinogens, and stimulants. The drug categories would likely produce symptoms of flaccid muscles are narcotic analgesics, inhalants, and depressants. Additionally, depressant tends to have no effect on muscle tone. While muscle tone is important to note, the DRE is trained to account for an individual’s body fat content, which could affect these observations. The evaluator should be diligent in their evaluation of muscular persons, since their muscle tone is normally rigid. The same hold true for individuals who are overweight, since their normal muscle tone is usually flaccid.
Often, drugs are introduced into the system by way of injection through the use of hypodermic needle. The needle punctures the skin and enters a vein. Once this is accomplished, the user injects the substance into the vein so that it can be distributed through the blood stream to achieve the desired effect.
The main area of concentration for injection sites are around the arms, in between the fingers, and around the base of the neck, or in places that have accessible veins. The DRE, in addition to checking for muscle tone, also looks for signs of intravenous drug use. Scarring in and around vein lines or raised bumps or welts may indicate injection of a drug into the system.
Whenever an injection site is found by the DRE, a schematic light with magnifier lens is used to assess the mark. Notations of hypodermic needle marks may assist the DRE in determining what categories of drugs may have been used. Drug categories that are most often associated with needle use are narcotic analgesics; however, some stimulants are introduced in this manner as well.
Based upon all the available information gathered from the Drug Influence Evaluation (DIE) to this point, the DRE should have some idea about what category of drug was used. This hypothesis is based on the physical and observable manifestations exhibited by the evaluated individual during the nine previous steps. Having made sure that the evaluated individual’s constitutional rights have been given and understood, the DRE interviews the individual, asking specific questions concerning drug use and category. The statements given by the evaluated individual are used to support the DRE’s prediction of what particular category drug was used.
During this portion of the evaluation, the DRE should be aware that suspects make numerous spontaneous statements that may incriminate themselves. The DRE should make note of these types of statements that in the main element of this phase of the evaluation.
By this point on the evaluation, the DRE should have formed an opinion of the category of drug(s) responsible for any observed impairment. This opinion should be based on a totality of the available information gathered in the evaluation.
The final step in DEC evaluation is to obtain a blood or urine specimen from the individual being evaluated and forward it to a laboratory for analysis. The analysis is conducted to determine if a drug is in the system of the individual as well as to identify the drug, if present. The toxicological analysis is then used to verify the category of drugs the DRE indicated based on their evaluation.
The result from the laboratory provides corroboration and substantiation of the DRE’s conclusions drawn from the previous 11 steps of the procedure conducted prior to submission of the sample. What should be emphasized is that the role of toxicology in the DEC program is corroborative rather than conclusive. Toxicology provides a scientific measure that supports the fact that a person has at some time ingested a drug.