What’s the history of the Drug Recognition Expert Program?
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Background:
The Drug Recognition Expert (DRE) Program is the preeminent training school for law enforcement officers to learn to recognize drug and alcohol impairment. It’s based on a deeply researched understanding of how a variety of substances impact the physiology of a user. In short, the tests include a variety of balance, divided attention, and eye movement tests which, when properly conducted are very accurate in determining impairment. The program was designed to give these highly trained officers the ability to detect impairment, and define the substance that users are impaired on, using only their observations. As long as these tests are conducted precisely according to how they have been developed and researched, law enforcement officers are able to determine impairment with good accuracy (about 68%).
Prior to the creation and certification of the Drug Recognition Expert (DRE) program, officers had very limited tools to police an increasing number of impaired drivers. It was well known that alcohol and other drugs had impairing effects on motorists, and it was similarly known that different substances impact drivers in different ways. So, very experienced officers were sometimes able to determine what substance a driver was impaired on, but training younger officers to do the same was nearly impossible. It was up to the younger officers to simply learn from their more experienced counterparts and adopt some of the same “tests” that those officers were using to determine impairment.
The tests used by officers to determine impairment varied widely, and none of them had scientific backing. That is, law enforcement officers had created some tests that seemed to indicate when someone was impaired, but the procedures for those tests, and passing that institutional knowledge on was not formalized. Officers often learned tests, then modified them to suit their personal experience, or the situation.
Some examples of non-standardized impairment tests that officers used include:
Reciting the alphabet backwards
Picking up a coin on the ground
Counting backwards from 100
Walking a straight line
Standing on one leg
Touching the nose with one finger
Following a pen-light with the eyes
Other balance and coordination tests
Other divided attention tests
As a law enforcement officer matured in their career, they would often develop and innate sense for whether or not a motorist was impaired, and what the substance they were impaired on was. However, that innate sense is not provable in a court of law. So, when an officer made an arrest decision based on the subject’s performance of these non-standard tests, there was little evidence that could be presented that would convince a jury of the person’s guilt.
When breath alcohol testing devices were introduced, they added a significant evidentiary asset to the impaired driving case. For the first time, there was concrete evidence of impairment to fall back on when the defense inevitably questioned the officers in court. The officer’s expert testimony continued to be relied heavily upon, but the finally had some impartial data to show the jury.
The advent of breath testing devices did not supplant the Drug Recognition Expert program for a few important reasons. First, the small portable breathalyzer devices (known as Portable Breath Tests, or PBTs) have never been accurate enough to be admissible in court. They are useful only for establishing probable cause, and the results they generate may not be used in court as conclusive evidence of impairment. Next, in case the evidentiary breath alcohol testing devices were not functioning properly, or had not been calibrated recently, the officers needed to have evidence of impairment. Then there’s the reality that not all impaired drivers were impaired on alcohol. If someone blew a 0.00 or a showed a low amount of alcohol in their breath, but were still acting impaired, the officers needed to be able to determine the substance and degree of impairment. Lastly, the challenges of prosecuting a DUI in court are such that additional evidence is almost always helpful to securing a conviction. These factors all have contributed to a need for the DRE program to not only continue, but to train more officers.
So, why not just have medical staff evaluate the arrestee for impairment using the DRE skillset? The primary reason is that there can be a significant waiting period before a suspect could be evaluated by medical staff. Several hours wasn’t uncommon when the DRE program was being developed, and that’s still often the case during busy days. This can cause the experienced impairment to be diminished by the time the suspect is evaluated. If the effect of the drugs had worn off, there may not have been enough evidence to convict. Officers had to have a way to determine impairment themselves.
Poly-drug impairment, or impairment arising from the use of multiple drugs at the same time, is also a confounding issue. Suspects can exhibit different signs and symptoms of impairment depending on what substances they used, and at what time. Officers therefore need to be able to determine active impairment, and potentially do so multiple times so that they can appropriately document the observed effects. For example, if a user takes both cocaine and heroin, the effects of cocaine may dominate initially, but the effects of heroin will become more pronounced over time since its impairment lasts longer.
Officers required a standardized, formalized, and researched way of determining and documenting observed impairment. When they make contact with a suspected impaired driver, officers are now taught a three-phased approach to detecting impaired drivers. First, the officer observes characteristics of impaired driving from a vehicle in motion. Next, they make personal contact with the driver of the vehicles, and lastly, the officer performs a pre-arrest screening of the driver. Officers learn a simple decision tree for use in these scenarios. In each step, the decision is either to proceed to the next step, or having determined the driver is not impaired, stop the process. At the end of this decision tree, is the arrest of the offending motorist or the decision to not arrest them with the knowledge that they are not impaired.
Standardized Field Sobriety Test (SFST) Development:
Also known by police officers as “FSTs”, the Standardized Field Sobriety Tests were developed largely thanks to the research of Dr. Marcelline Burns of the Southern California Research Institute (SCRI). She was able to conduct extensive research, with which she created the procedures that officers could then use to determine impairment. These tests could be conducted in a roadside environment, which made them immediately and immensely valuable for determining impaired driving. The Department of Transportation agreed that these tests were accurate and with that agency’s blessing, they became required curriculum for law enforcement officers.
It’s worth noting that these tests were originally developed to determine if a subject was over the legal limit at the time, which was 0.10% BAC - higher than what is today’s legal limit, 0.08% BAC. The tests were designed to evaluate a person’s ability to divide their attention and remain accurate in following simple instructions, while also demonstrating no physical signs of impairment. An impaired person will often forget parts of the test instructions or will fail to complete the test entirely. Stumbling, swaying and a lack of coordination are all physical signs of impairment.
The need for these tests arose from a dramatic rise in the number of drug impaired drivers that officers were encountering on the nations roads. From an increased likelihood of accident to poor driving behavior, this rise in impaired driving made the need for the SFSTs increasingly front of mind. Los Angeles was a hotbed of drugged driving, which naturally led to the Los Angeles Police Department (LAPD) being innovators in detecting and quantifying impaired drivers. These officers worked with doctors, psychologists and officers from their own Narcotics Division to create tests that would be repeatable and accurate.
Using the SFSTs for Drug Categorization:
Using extensive study of the impacts of drugs on the human body, the Drug Recognition Expert program divides drugs into seven major categories. These are based on shared patterns of effects, rather than strict chemical structure comparison. Each category of drug produces signs, which are detectable by an observer, that can be pattern-matched to the substances that produce them. The categories of drugs for the DRE program include:
Cannabis
Central Nervous System (CNS) Depressants (including Alcohol)
Central Nervous System (CNS) Stimulants
Narcotic Analgesics
Inhalants
Dissociative Anesthetics
Hallucinogens
When developing the categories, the LAPD relied heavily on knowledge from medical professionals, impairment researchers, and the officers that worked to combat impaired driving. The result was a systematic series of tests that allow a highly trained officer to accurately categorize the category of substance that the person was impaired on. This work was conducted in the early 1980’s and has stood the test of time, both in terms of scientific rigor, but also in acceptance by courts.
The modern Drug Recognition Expert (DRE) Examination:
Today, using a checklist of procedures, all officers are able to perform the Standardized Field Sobriety Test, or SFST. These are the simplest to perform and interpret and produce a reasonably reliable picture of the impairment or sobriety of the subject.
The Standardized Field Sobriety Tests include:
Walk and Turn: The test subject is instructed to walk a line with one foot in front of the other, with the feet placed heel to toe. They walk a straight line forward, turn and come back.
One Legged Stand: The test subject is instructed to stand with the feet together, then raise one foot off the ground, and count while maintaining balance.
Horizontal Gaze Nystagmus: The test subject is instructed to follow a stimulus, typically a finger tip or pen light, with their eyes only. This test looks for their ability to smoothly track a stimulus first. It then tests for the presence of nystagmus, or involuntary twitching of the eyes, when the eyes are moved on a horizontal plane. Importantly, the test subject must exhibit distinct and sustained nystagmus at maximum deviation (on the periphery). They may also exhibit nystagmus with an angle of onset prior to 45 degrees.
The Drug Recognition Expert tests expand considerably on the SFSTs conducted by the average officer. They’re complex, and require both training and regular refresher courses to conduct accurately. The 12-step process is challenging for officers and requires considerable time to administer. For this reason, it’s rarely, if ever, used in a roadside setting.
Breath Alcohol Test: The officer conducts a breath alcohol screening, typically on an evidential quality device. If this test shows that the subject is not impaired on alcohol, or that the level of alcohol in their breath doesn’t sufficiently explain the impairment they’re displaying, the officer will continue with the DRE evaluation.
Interview: The DRE officer will interview the arresting officer to determine what they observed in the field, and why they performed an arrest on the subject. They will learn about the subject’s behavior, any traffic infractions that were observed, and what field evaluations were done.
Preliminary Examination with First Pulse Measurement: The DRE officer will conduct an evaluation on the subject, including checking their pulse. The examination will attempt to determine (and elicit a confession) of what drugs the subject has used. The officer will note the mannerism, attitude, speech, coordination, breath, and any other physical symptoms. The pulse rate is taken a total three times during the DRE evaluation; this step includes one of those. The officer will also attempt to determine if the subject may be suffering from a medical condition.
Eye Examination: The officer will evaluate the subject for indications of impairment that manifest in the eyes. That includes the following tests - Lack of Convergence; Distinct and Sustained Nystagmus at Maximum Deviation; Horizontal Gaze Nystagmus with an Angle of Onset Before 45 Degrees; Vertical Gaze Nystagmus; and Lack of Convergence. Note - these tests (plus Pupillary Rebound Dilation) are the exact same ones conducted by the Gaize headset.
Divided Attention Physical Tests: Next, the officer evaluates the subject on a series of physical tests that are designed to elicit errors if the subject is impaired. These include the following tests - Modified Romberg (balance test), Walk and Turn, the One Legged Stand, and the Finger to Nose Test.
Vital Signs with Second Pulse Measurement: The officer performs a second pulse measurement, and measures the subject’s temperature and blood pressure. Variations from normal measurements can be signs of impairment.
Dark Room Evaluation: The DRE then measures pupil size during three different light conditions. First, the subject’s pupils are observed and measured in room light conditions. Next, the room is blacked out for 90 seconds to allow the subject’s pupils to fully dilate. Lastly, the subject’s eyes are exposed to bright light to test their ability to constrict and remain in a constricted state (also known as Pupillary Rebound Dilation, which is the final test that the Gaize headset performs).
Muscle Tone Evaluation: The officer next tests the subject’s muscle tone for signs of rigidity or flaccidity. Both of these are indicators of impairment on certain drugs.
Check for Injection Sites and Third Pulse Measurement: In this step, the DRE examines the subject’s body in common locations for intravenous drug use. These include the arms, legs, and feet. The subject’s pulse is also taken for the third and final time.
Subject Interview: The DRE next reads the subject their Miranda Rights if they have not had them read already, and conducts an interview with the subject regarding their use of drugs. The officer is trying to get an admission of drug use in this step.
Analysis of Evaluation: Based on the evaluation conducted, the DRE forms an expert opinion of the state of impairment and the type (category) of drugs they believe the subject is impaired on.
Toxicological Examination: The final step is a toxicological examination, typically performed using a blood draw, to capture additional evidence to support the DRE’s opinion of impairment.
Clinical Validation:
The obvious question that one asks when learning about the Drug Recognition Expert evaluation for the first time is: how accurate are these specially trained police officers? The answer is quite accurate. This may surprise some people - after all, how can a human being accurately detect and classify drug impairment with a person who’s trying to hide it, and is often non-cooperative?
Each category of drugs has a unique way in which it impacts the body. It’s these unique clues that create a body of evidence that the officer can assemble to determine drug impairment. For the most part, it’s difficult to determine what drug an individual is impaired on within each category, but very possible to determine the category as a whole. For example, an officer can likely determine if an individual is impaired on a Central Nervous System (CNS) Stimulant, but won’t be able to know whether the person is impaired on meth, cocaine, speed, or another drug without a chemical analysis (usually blood work).
When the Los Angeles Police Department began using the DRE process broadly in the 1980s, the National Highway Traffic Safety Administration (NHTSA) decided to step in and evaluate the procedures for accuracy. They correctly saw that the DRE evaluation, if proven to be accurate, could be a national model for training police officers to determine drug impairment. An agency within the US Federal Government, the NHTSA was well positioned to evaluate and ultimately adopt the DRE training protocol as the national standard. In 1984, the NHTSA and the National Institute on Drug Abuse sponsored a laboratory evaluation of the DRE evaluation at Johns Hopkins University.
For the study (full published study linked here), several LAPD Drug Recognition Experts visited Johns Hopkins and were subjected to a double-blind trial in which 80 participants received either a placebo, or one of two dosages of the following drugs: cannabis, diazepam (a benzodiazepine), amphetamine (AKA speed, a CNS stimulant), or secobarbital (a CNS depressant). The LAPD officers were charged with completing a DRE examination on each subject and determining whether or not they were impaired, and on what type of drug the subject was impaired on. This resulted in the first objective data of the accuracy of the Drug Recognition Expert process and the results were very good. In the study, the DREs were over 90% accurate in determining if the subject was impaired and on what type of substance.
The DRE examination was again evaluated for accuracy in 1986 with a study on 173 drivers who had been arrested under suspicion for driving while impaired on drugs (the study is linked here). The National Highway Traffic Safety Administration evaluated blood samples from the subjects and compared that to the evaluations done by Drug Recognition Experts. They concluded that the DREs were 94% accurate in determining the presence of drug impairment (not factoring in the category of impairing substance). A notable complication in this study arose when it was determined that most (over 70%) of the drivers had more than one drug in their blood sample. The officers were 87% accurate at determining either all or at least one of the impairing drugs present. The DRE officers were incorrect in determining the category of impairing substance in 13% of the drivers, and in one driver, no drugs or alcohol were found.
Later studies have further demonstrated that DRE trained officers are extremely accurate in determining active drug impairment.
National Adoption:
The success of the DRE evaluation process in the studies in the 1980s led to a surge of national interest. Many departments were now interested in how they could have their officers trained as Drug Recognition Experts. Since the training curriculum was more or less informal, there was a huge effort led by the Los Angeles Police Department and overseen by the National Highway Traffic Safety Administration to formalize the curriculum. The result was a standardized set of training resources that allowed for highly repeatable classes that produced highly trained Drug Recognition Expert Officers. This was completed in 1987 and the first class using the standardized curriculum was held in Los Angeles that year.
The NHTSA then selected four states (Arizona, Colorado, New York, and Virginia) to be the first to pilot the DRE process outside of Los Angeles. These states had emerged as leaders in impaired driving enforcement and signaled their interest in deploying DREs in their jurisdictions. To stand up the first remote training centers for Drug Recognition Experts, each of these states sent officers to be trained as DRE instructors, and the LAPD then sent representatives to monitor the new training programs.
While these training programs were being developed and implemented, the International Association of Chiefs of Police (IACP) was monitoring the program and advised the LAPD and NHTSA on national expansion plans. In 1988, with support from the IACP, the US Government passed the Omnibus Drug Act, which was broad legislation that tackled the issue of drug use in the United States. Among many other provisions, this law funded the national expansion of the DRE program. After being close to the process in an advisory capacity for years, the IACP assumed oversight of the DRE program in 1989. This change made the IACP the governing body for the drug recognition expert program, and the organization that certifies all DRE officers today. The program’s name is now the “Drug Evaluation and Classification Program” (DECP, or DEC).
Seeing the success of the DRE program in the United States, several other countries have adopted the methodology. Today, DREs operate in Australia, Canada, Norway and Sweden.
Controversy:
The Drug Recognition Expert program has been remarkably successful at removing impaired drivers from the United State’s roadways. However, the program has also had its share of controversy to go along with the success. Detractors claim that the process lacks scientific rigor and objectivity. Given the strongly human-centric nature of the DRE examination, the concerns in this area are not without merit. Officers almost certainly have personal biases and an expectation of finding impairment when conducting one of these evaluations, which are inescapable.
Courts regularly recognize DRE officers as “experts,” allowing them to render opinions rather than simply state facts. This radically increased the conviction rate for DUI-drugs, which has in turn caused many to question the accuracy of the tests and the assertion that DRE officers are truly experts. There is a question as to whether the opinions rendered by DRE officers are “medical” and if they are medical, whether or not the officer is adequately trained to form a medical opinion.
The state of New Jersey currently recently re-affirmed the validity of the DRE evaluation process in State v. Olenowski. This case was carefully monitored by both proponent and opponents of the DRE program. Validation of the program was a huge win for the law enforcement community, and serves to add additional credibility to this process.
Conclusion:
The Drug Recognition Expert program has been remarkably useful in removing impaired drivers from the US’s roadways. This has no doubt saved countless lives and has allowed officers to successfully prosecute drug impaired drivers. Since no technology solution to detecting drug impairment has existed before, the challenge has only been able to be met using a human conducted evaluation process.
Training more DRE officers should be a goal of law enforcement agencies so that more drug impaired drivers can be found and stopped. However, this training program is very challenging and not all officers will be successful in completing it. The national shortage of DRE officers is even more vitally important to tackle since the legalization of cannabis is proceeding rapidly, and no chemical test can detect impairment.
While DRE evaluations are very accurate, they’re not perfect, and the inescapable subjectivity of the evaluation of results by a human being causes concern for many. The greatest improvement to the DRE process would be replacing human-centric processes with data-driven ones. Such a change would allow for objectivity and fairness to be further injected in to the process. This is precisely the change that Gaize is seeking to drive using automated eye tests and highly specific algorithms to classify impairment.
