Accuracy of Drug Recognition Evaluations

October 5, 2020

Carol Stream police Sgt. Brian Cluever pulls over a motorist in

Carol Stream on Dec. 7, 2017. (Antonio Perez / Chicago Tribune)

With the legalization of medicinal marijuana in 33 states (plus D.C.) and 11 states (plus D.C.) where recreational marijuana is legal, it has become necessary for police to be able to evaluate individuals based on suspicion of impaired driving due to drug use. A Drug recognition expert or drug recognition evaluator (DRE) is a police officer trained to recognize impairment in drivers under the influence of drugs other than, or in addition to, alcohol.

The Los Angeles Police Department originated the program in the early 1970s, when LAPD officers noticed that many of the individuals arrested for driving under the influence (DUI) had very low or zero alcohol concentrations. The officers reasonably suspected that the arrestees were under the influence of drugs but lacked the knowledge and skills to support their suspicions. In response, two LAPD sergeants collaborated with various medical doctors, research psychologists, and other medical professionals to develop a simple, standardized procedure for recognizing drug influence and impairment. Their efforts culminated in the development of a multi-step protocol and the first DRE program. The LAPD formally recognized the program in 1979.

The LAPD DRE program attracted NHTSA’s attention in the early 1980s. The two agencies collaborated to develop a standardized DRE protocol, which led to the development of the DEC Program. During the ensuing years, NHTSA and various other agencies and research groups examined the DEC Program. Their studies demonstrated that a properly trained DRE can successfully identify drug impairment and accurately determine the category of drugs causing such impairment.

How Do Police Determine Whether a Driver Is Under the Influence?

1. Observations

Police reports commonly contain an account of the arresting officer’s observations at the traffic stop that led them to suspect a possible DUI. Some observations of alcohol impairment include:

• Slurred words
• Stumbling
• Nodding off
• Bloodshot or watery eyes
• The smell of alcohol
• Open containers in the vehicle

Some signs of possible drug impairment that officers regularly cite include:

• Bloodshot or glassy eyes
• The smell of marijuana
• Disorientation
• Talking fast, moving around, or unnaturally high energy
• Drowsiness

Alcohol and different types of drugs affect each person in a different way. Therefore, officers will cite any possible observations of intoxication they can. Sometimes, such characteristics may occur due to fatigue, illness, or other completely legal factors. Defense attorneys closely examine police reports and challenge officers regarding their alleged observations of impairment.

2. Field Sobriety Tests

• Walk and turn
• Horizontal gaze nystagmus
• One leg stand

During these tests, officers should be trained to take note of many factors and behaviors of a subject, including the ability to follow directions, ability to balance, involuntary reactions in the eyes, and more. If you “fail” one or more FSTs, an officer can use that as probable cause to make an arrest.

One problem with FSTs is that the driver is already in an inherently stressful situation—whether they were drinking or not. Police encounters can be intimidating, and pressure or nervousness can cause an FST participant to make mistakes, even though they were not under the influence. Some officers also do not have the proper training to conduct FSTs or fail to conduct the tests in accordance with the required standards. Lawyers regularly challenge FST evidence in DUI cases.

3. Blood Tests

Officers may request that you submit a blood sample to measure your BAC or to see if there are drugs in your system. Similar to a breath test, implied consent laws mandate that drivers agree to such testing. While prosecutors rely heavily on blood test results in DUI cases, there are several reasons these tests may be inaccurate or may not indicate driving under the influence:

• The forensic lab made errors handling or testing the blood sample
• Drugs can remain in your system for days or weeks after using, so levels of drugs in your system do not necessarily mean you used drugs in the past few hours before you drove

There’s been a lot of concern that police don’t have an easy, accurate way to test drivers for impairment due to marijuana like they do for alcohol. What’s less well known is that they don’t have a similar test for opioids, methamphetamines, or many other intoxicating substances, either.

In several states, trials are underway using mouth swabs that may be able to determine levels of a half-dozen drugs, not just the presence of drugs. Until then, what may be the best method available, originated, as so many things do, in Los Angeles, California. It may not be good enough. A DRE officer track record seems to be around 85 %. Atlanta, Georgia TV station WXIA Channel 11’s 11 Alive Investigators pointed out that “independent studies” rated a DRE’s accuracy as only about 50-50.

Cannabis remains in the body long after intoxication ends – days, weeks or even months afterward. THC does remain in urine longer than in blood. In some European countries, urine first and then blood are tested, with any trace evidence enough for a charge of driving under the influence.

This false confidence in the face of the facts may be the best argument against the use of DREs.

The Canadian Broadcast Corporation’s The Fifth Estate also found the tests are prone to bias and false positives, further noting that six US states’ courts have refused to let DREs testify as experts, including California, the birthplace of the DRE. A Maryland court stated that DRE training “does not enable DREs to accurately observe the signs and symptoms of drug impairment,” so DRE conclusions aren’t accurate or reliable.

Few tests are 100 % accurate, drugged driving is a bad and increasing problem. Police and politicians could argue that no harm is done using a DRE.

They would be wrong.

• The DIE test can last 45 minutes and is extremely subjective. Told to walk an imaginary line, the DRE gave one suspect demerits for an “improper number of steps.”
• It is scary to be arrested, especially if you’re innocent, even if it’s only overnight. You feel like a character in a Kafka novel, especially if the police won’t believe the blood or urine test results. Sandra Bland committed suicide while in police custody when a traffic stop escalated. The officer wasn’t a DRE, and drugs weren’t suspected, but it’s still an object lesson.
• It can be expensive. One of the plaintiffs in the federal lawsuit had legal fees in the thousands of dollars because of her arrest.
• One of the Cobb County suspects lost her job because she was arrested on a drug charge, costing her an alcohol server’s license.

Part of the problem is that the suspects were arrested for minor traffic violations such as briefly crossing or touching the lane line. That would not normally even rate a ticket unless it was part of an observed pattern of behavior.

In their panic to cope with new, unfamiliar, and difficult to detect intoxicants, law enforcement is putting too much faith in a questionable test.

An example of citizens fighting DRE results.

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