The Drug Recognition Expert Police Officer: A Response to Drug-Impaired Driving Page, T.E. Los Angeles Police Department P.O. Box 50332, Pasadena, California 91115-0332 USA Keywords: Drugs, DRE, Drug Recognition Expert, Driving, DUI, DWI, police, LAPD Abstract: Law enforcement agencies in thirty-four United States and British Columbia, Canada, rely on Drug Recognition Expert (DRE) officers to apprehend the drug-impaired driver. DREs utilize a systematic and standardized twelve-step procedure to reach three determinations: (1) that the driver is impaired; (2) that the driver is impaired by drugs, rather than suffering from a medical condition that requires intervention; and (3) the category of drug (s) that is causing the impairment. The admissibility of DRE opinion testimony, usually in conjunction with corroborative toxicological analysis, has been upheld in many courts throughout the U.S. The seven DRE drug categories are not based on shared chemical structures, legality, or use if any in treatment of illness or disease. Rather, the categories are based on shared patterns of signs and symptoms. The categories used by DREs are: Central Nervous System (CNS) Depressants, Inhalants, Phencyclidine, Cannabis, CNS Stimulants, Hallucinogens, and Narcotic Analgesics. The prevalence of poly-drug use complicates the DRE determinations. This paper will provide an overview of the DRE procedures, DRE drug categories, and the DRE training program. Body: The Drug Recognition Expert (DRE) Program and procedures were initially developed in the late 1970's by traffic enforcement officers of the Los Angeles Police Department. This program trains selected officers to utilize a step-by-step evaluation procedure, enabling the DRE officer to determine if an individual is under the influence of drugs, and then to determine the type of drug causing the observable impairment. The procedure enables the DRE to rule in (or out) many medical conditions, such as illness or injury, that may be contributing to the impairment. Although the primary focus of the DRE program is driving under the influence (DUI) enforcement, the procedures have been applied to many other areas where identification of the drug-impaired individual is important.
The accuracy of the procedure used by DREs was initially validated in two controlled studies. A 1984 research study at Johns Hopkins University showed that Los Angeles DREs were able to accurately distinguish between the drug-impaired and non-drug-impaired individual. A subsequent Field Validation Study (173 case study) sponsored by the U.S. National Highway Traffic Safety Administration (NHTSA) in 1985 evaluated the accuracy of the DRE procedures in actual arrest situations. Again, the DREs were very successful in identifying both the drugimpaired individual and the class(es) of drug(s) causing the impairment. Subsequent studies of the DRE protocol and program in other jurisdictions, particularly Arizona, supported the conclusions of these initial studies. The success of these studies has precipitated the dissemination of DRE techniques to law enforcement officers in 34 states, the District of Columbia, and British Columbia, Canada. As of November, 1999, nearly 5,000 officers maintain DRE certification. Since 1989, DRE training and certification have been regulated by the International Association of Chiefs of Police (IACP). NHTSA continues to support the DRE program, which is now formally titled the Drug Evaluation and Classification Program. The DRE procedures have been subject to numerous defense motions challenging the admissibility of DRE testimony. Thus far, courts in California, New York, Arizona, Minnesota, Colorado, Hawaii, Iowa, Oregon, Washington, Nebraska and Florida have upheld the admissibility of DRE evidence. As an example of DRE's acceptance in court, the Los Angeles City Attorneys Office has estimated that 95% of those charged with driving under the influence of drugs are convicted in LA courts. Although a DRE may initiate an arrest for DUI-drugs, the usual case is for a different officer, the arresting officer, to request the expertise and assistance of the DRE after making a DUI arrest. Simply, the arrestee may appear more impaired than the alcohol level alone would account for. Some agencies mandate a drug influence evaluation by a DRE whenever an individual is arrested for DUI and produces a BAC below the statutory per se level. A DRE is responsible for making three determinations: (1) the arrestee's impairment is not consistent with the BAC; (2) the individual is under the influence of drugs, and not suffering from a medical condition that requires immediate attention; and (3) the individual is under the influence of a specific category (or categories) of drugs. 2 In order to reach an opinion that the individual is under the influence of a specific category (or categories) of drugs, DREs utilize a 12 step standardized process. Step One: BAC This step often precedes the involvement of the DRE. If the arresting officer has determined that the BAC is consistent with both the type and degree of impairment, no DRE is called.
Step Two: Interview of the Arresting Officer Based on the results in Step One, the arresting officer requests the assistance of a DRE. The DRE will discuss the circumstances of the arrest with the arresting officer. Step Three: Preliminary Examination The purpose of this step is to determine if there is sufficient reason to suspect drug influence. The DRE makes observations of the arrestee's condition, inquires of the arrestee as to any health problems, and conducts a pupil size and eye tracking examination. In addition, the DRE takes the first of three pulses in this step. Step Four: Eye examination During this step, the DRE conducts three separate eye movement examinations. They are: horizontal gaze nystagmus, vertical gaze nystagmus, and an eye convergence examination. Step Five: Divided Attention Testing The DRE administers the following divided attention tests in the following order: modified Romberg Balance Test, a Walk and Turn Test, the One-Leg Stand Test, and a Finger-to-Nose Test. Step Six: Vital Signs Examination The DRE takes three vital signs: blood pressure, body temperature and pulse. This is the second of three pulses, the first having been taken in the preliminary examination. Step Seven: Darkroom Examination The DRE uses a pupillometer to estimate the arrestee's pupil sizes in four different light levels: room light, near total darkness, indirect artificial light, and direct light. The DRE also examines the individual's nasal and oral cavities for evidence of drug use. Step Eight: Muscle Tone The arrestee's muscle tone is evaluated throughout the examination, through observations of the arrestee's movements. During this step the DRE gently moves the arrestee's arms to determine muscle tone. Step Nine: Injection Sites Examinations During this step, the DRE examines the individual for injection sites. Although the drug user may inject anywhere on the body, the more frequently used areas are the arms, neck, and ankles. A third pulse is also taken. Step Ten: Statements, Interview In accordance with the arrestee s constitutional rights, the DRE questions the person about the use of specific drugs. The DRE may ask the arrestee about any warnings given to the arrestee by a prescribing physician or pharmacist regarding operating a motor vehicle while taking the drug.
Step Eleven: Opinion The DRE now forms an opinion as to drug influence, and the category(s) of drug(s) causing the impairment. As written, a typical DRE opinion is: "In my opinion, the arrestee is under the influence of a Central Nervous System Stimulant, and cannot safely operate a vehicle." Step Twelve: Toxicology: Specimen and Subsequent Analysis During this step, the DRE obtains a urine and/or blood specimen from the suspect, which is then analyzed for the presence of certain drugs by a toxicological laboratory. Typically, a week or more will elapse until the laboratory reports their results. The decision to prosecute the individual will usually be delayed until these results have been obtained. In court, the consistency between the DRE's opinion and the laboratory analysis is critical in demonstrating the accuracy of the DRE. DRE Drug Categorization: Based on Patterns of Signs and Symptoms Drug Recognition Experts classify the drugs of abuse into seven categories. This categorization system is based on the premise that each drug within a category produces a pattern of effects, known as signs and symptoms. Practically, this means that although there are numerous drugs within each of the seven categories, the overall pattern of effects within the category at hand is the same. The effects can and do vary from drug to drug, primarily in terms of intensity and duration of action. The seven DRE drug categories are: CNS Depressants (including alcohol), Inhalants, Phencyclidine, Cannabis, CNS Stimulants, Hallucinogens, and Narcotic Analgesics. Central Nervous System Depressants In addition to alcohol, this category includes barbiturates, non-barbiturates that have barbituratelike effects, anti-anxiety tranquilizers, anti-psychotic tranquilizers, certain anti-depressants, and certain pharmaceutical combinations that contain more than one type of CNS Depressant. The benzodiazepines, chloral hydrate, GHB, methaqualone (Mandrax), lithium, phenobarbital, the sedating antihistamines, and many other substances are included in this category. Inhalants Three sub-categories comprise the inhalants: volatile solvents, aerosols, and anesthetic gases. Included are solvents, such as paint thinner, gasoline, toluene, turpentine, and paint. Nitrous oxide ("laughing gas"), Freon, ether, and many other substances are also included. Phencyclidine (PCP) This drug is usually known as PCP, which represents its longer chemical name of phenylcyclohexyl piperidine. It is also commonly called phencyclidine. PCP is appropriately termed a dissociative anesthetic. The drug ketamine, which has uses in veterinary medicine, in pediatric surgery, and in other areas, is included in this category, as are chemical analogs of PCP. Cannabis This category includes marijuana, hash, hash oil, and the synthetic drug dronabinol.
Central Nervous System Stimulants This category includes cocaine in all its various forms, amphetamine, methamphetamine, ephedrine, Ritalin, certain diet pills, and other related substances. Hallucinogens LSD, psilocybin, mescaline, peyote, bufotenine, morning glory seeds, jimson weed, nutmeg and the psychedelic amphetamines are some of the drugs in this category. The psychedelic amphetamines include MDMA, or methylenedioxy methamphetamine, which is known in the vernacular as "Ecstasy," and many other related preparations. Narcotic Analgesics This final category includes the opiates, such as morphine, codeine, percodan, heroin, meperidine, methadone, fentanyl, and numerous others. Poly-drug Use Poly-drug use is a frequently encountered complicating factor in a DRE evaluation. The polydrug user may exhibit unpredictable mixtures of signs and symptoms. DREs apply four concepts to interpret poly-drug signs and symptoms: additive, antagonistic, overlapping, and null. The DRE Training Course: An Overview In order to attend DRE training, the candidate is typically nominated in writing by the officer's commanding officer. The criteria for selection include a demonstrated aptitude and interest in DUI enforcement and/or narcotics enforcement. Candidates must also have demonstrated an ability to conduct thorough crime scene investigations, and to testify clearly and convincingly in court. DRE training and eventual certification consists of the following components: 1) Standardized Field Sobriety Test (SFST) training (two to three day course) 2) DRE preliminary training (two day course) 3) DRE School (seven days) 4) DRE School Classroom Examination 5) Minimum number of evaluations (minimum of twelve) 6) Minimum number of drug categories observed (minimum of three) 7) Toxicological corroboration (minimum rate of 75%) 8) "Rolling" log reviewed 9) Resume reviewed 10) Certification knowledge examination 11) Endorsement by an instructor 12) Endorsement by a second instructor 13) Certification issued by the International Association of Chiefs of Police. DRUG SIGN AND SYMPTOM MATRIX CNS DEPRESSANTS INHALANTS PCP CANNABIS CNS STIMULANTS HALLUCINOGENS NARCOTIC ANALGESICS
HORIZONTAL GAZE NYSTAGMUS CNS DEPRESSANTS INHALANTS PCP CANNABIS CNS STIMULANTS NOT HALLUCINOGENS NARCOTIC ANALGESICS NOT NOT NOT VERTICAL NYSTAGMUS POSSIBLY POSSIBLY USUALLY NOT NOT NOT NOT LACK OF CONVERGENCE NOT NOT NOT PUPIL SIZE WITHIN THE RANGE RANGE OR DILATED WITHIN THE RANGE DILATED BUT MAY BE DILATED DILATED CONSTRICTED REACTION TO LIGHT SLOWED SLOWED SLOWED LITTLE OR NO VISIBLE REACTION PULSE RATE BELOW BELOW BLOOD PRESSURE BELOW DEPENDS ON SUBSTANCE BELOW BODY TEMPERATURE References: WITHIN THE RANGE, BELOW, OR WITHIN THE RANGE BELOW Drug Recognition Expert (DRE) Validation Study, Final Report to Governor's Office of Highway Safety, State of Arizona, June 4, 1994. Eugene V. Adler, Arizona Department of Public Safety and Marcelline Burns, Southern California Research Institute. Evaluation of the Impact of the Drug Evaluation and Classification Program on Enforcement and Adjudication, December, 1992. D.F. Preusser, R.G. Ulmer and C.W. Preusser. Report no. DOT HSA 808 058. Field Evaluation of the Los Angeles Police Department Drug Detection Procedure. February, 1986, DOT HS 807 012, A NHTSA Technical Report, National Highway Traffic Safety Administration. Richard P. Compton. (Commonly referred to as the 173 Case Study). Identifying Types of Drug Intoxication: Laboratory Evaluation of a Subject Examination Procedure, May 1984 Final Report. George E. Bigelow, Ph.D. et al. Behavioral Pharmacology Research Unit, Department of Psychiatry and Behavioral Sciences. Funded by the U.S. Department of Transportation's NHTSA and the National Institute of Drug Abuse. (Commonly called the Johns Hopkins Study), NHTSA, Pub. No. DOT HS 806 753 (1985). A Study of Working Partnerships: A Report to Congress on the Drug Evaluation and Classification Program. National Highway Traffic Safety Administration, April 1, 1996