Dismantling the State’s DRE controlled substance DUI prosecution

The following is an excerpt from the Drug Recognition Expert and Cannabis Chapter that I wrote for publication by the Oregon Criminal Defense Lawyers Association in the 2020 version of the DUI Trial Notebook. The DUI Trial Notebook is used statewide to assist DUI and Criminal Defense Attorneys defend against alcohol and drug DUIs.

A DRE is brought in when an officer arrests somebody for DUI and they blow under the legal limit of 0.08%. This type of DUI enforcement has been picking up in recent years in Eugene and Springfield. The most commonly called substance of impairment is cannabis, followed by stimulants, depressants and narcotics. The DRE process is also often used in conjunction with prosecution of a DUI where people provide a breath sample below the legal limit of 0.08% but above 0.0%, this is a combined effects DUI. If you are being charged with a drug or alcohol DUI contact MJM Law Office, PC for more information.

Excerpt from the 2020 OCDLA DUI Trial Notebook:

“If the doors of perception were cleansed every thing would appear to man as it is, infinite.”  William Blake


If your client is arrested for DUI and provides a breath alcohol sample that is less than 0.08% there is a good chance the police will not apologize and release them from custody but instead bring in a “drug recognition expert” or DRE. A DRE is a police officer that has attended a specialized training program purported to enable them to tell if a person is impaired by drugs and if so which ones.

The police report will likely say something to the effect that defendant’s blood alcohol level was not consistent with the level of impairment so I brought in a DRE. A second officer is typically brought in even if the arresting officer is a certified DRE to create the illusion of impartiality. An important point about the DRE process to be aware of is that the DRE most likely knows the answer before beginning the test. By this point the arresting officer will have grilled your client relentlessly about the last time they smoked cannabis or used other drugs and have a pretty good idea of what they are looking for. Sometimes your client will be in possession of drugs which gives the DRE a pretty strong indication of what substance will be in the urine to confirm their opinion.

Do not be intimidated by a DRE DUII. This is a practice area ripe with opportunities to mount a strong defense against their voodoo science and provide alternative explanation for observations made by the DRE. The DRE DUII jury trial provides a wonderful opportunity to educate the jury about the DRE program and why it cannot prove beyond a reasonable doubt what if any drugs your client was on at the time of driving.

Think of yourself as a professor educating the jury on what the DRE program is, what observations the DRE made, and why that doesn’t go very far in determining with certainty whether there was impairment at the time of driving. You may want to use expert witnesses to help educate the jury, or you may choose to rely on the states own witnesses to support your theory of defense.

Practice Tip

Whenever possible use the State’s own witnesses to support your theory of defense. This will have a much greater impact on the jury since they may believe defense expert witnesses are hired guns that will say whatever we want them to. There can be little chance of bias if the State’s witnesses are providing testimony that we can use in closing to support our theory of defense.  A common theory of defense in a DRE DUII case is “my client was not under the influence of a controlled substance at the time of driving.” Bring out every piece of evidence in the State’s case in chief that supports this theory, and every piece of evidence that contradicts the State’s theory.

This chapter will begin by providing a brief history of the DRE program, then review some statistics of DRE cases in Oregon, then review the seven drug categories.  We will briefly review polydrug use and how a determination is made when a defendant is accused of being on multiple drugs. We will then review the DRE 12 step protocol and that case law that supports the DRE program as scientific evidence.  We will then explore the DRE matrix focusing on the four drug categories that are called 98% of the time (Cannabis, CNS Depressants, CNS Stimulants and Narcotics).

This section includes a deep dive into the Cannabis category, which made up 40% of the Oregon DRE calls in 2018.  We will resurface with some general defense strategies and practice tips to help you prepare for your DRE DUII trial. At the end of the chapter you will find a glossary of useful terms that will help you analyze your DRE case, a list of sample cross examination questions to ask the arresting officer, DRE and lab tech. Finally, we have provided an independent peer reviewed study that calls into question the accuracy and validity of the DRE program.

chapter gives citations to and relies heavily on the 2018 Drug Recognition Course Participant Manual. A copy of the close to 1,000 page document can be found in the DUII Trial Notebook Resource Guide. The Participant Manual is divided into 30 sessions and I have listed the session and page number when referred to in this chapter.

DRE DUII enforcement is an area of law that casts a particularly wide net that often captures innocent people that may have used controlled substances at some point in the past but were not impaired at the time of driving. We hope you find this chapter to be a valuable resource for defending those accused of this crime and being prosecuted by the use of this arbitrary pseudo-scientific process.

History of the DRE Program

According to the Los Angeles Police Department (LAPD) website, in the 1970’s the following scenario was regularly played out on the streets of American communities: While on routine patrol an officer makes a stop and completes a mental checklist: bloodshot eyes, check, slurred words, check, forgetting about the driver’s license, check, car smells like a brewery, check. “I think this guy might be deuce,” the officer thinks. “Deuce” is a slang term, primarily used in California, for a person who drives under the influence of alcohol.

“Duece” is derived from 502, a former California penal code for DUI. The LAPD article goes on to lament how the officer loses the deuce because the person blows 0% BAC and they do not have the evidence to convict for driving while under the influence of drugs. LAPD was frustrated at being unable to prosecute these cases and developed the first DRE program. Mixing together a potent cocktail of law enforcement, medicine, psychiatry, physiology and toxicology they developed a drug classification and identification program to secure more DUII convictions.

According to the IACP website, 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 drug recognition expert (DRE) program. The LAPD formally recognized the Drug Recognition Expert program in 1979.

The National Highway Transportation Safety Administration (NHTSA) took an interest in the LAPD program and collaborated with the LAPD to create the current Drug Evaluation and Classification Program (DECP) in 1984. In 1987, the Highway Safety Committee of the International Association of Chiefs of Police (IACP) partnered with NHTSA to roll out the DECP nationwide. In the 1980’s NHTSA sponsored three studies to validate the DECP and allow them to be used in court. These studies were reviewed by a neutral third party in 2013 and found to be flawed, biased and unscientific. See Kane Study in Appendix B. Oregon eventually adopted the DRE program in 1997 and as of 2018 Oregon had 212 certified DREs and 38 DRE instructors. (IACP 2018 annual report).

An ordinary officer can become a drug recognition expert after about two weeks of classes and a few field practice sessions. This is not the most sophisticated expert in the court room. The certification process includes a 16 hour “Pre-School,” a 56 hours DRE school (using the 2018 DRE Course Participants Guide), and then the officer must conduct at least 12 drug influence evaluations while under the supervision of a DRE instructor. The DRE student must pass a final written exam and show an accuracy of at least 75% based on toxicological confirmation. (Session 30 Page 10).

The DRE must then be re-certified every two years by showing they have completed at least four acceptable drug evaluations, completed at least eight hours of approved re-certification training and presenting an updated CV and rolling log. (Session 30 Page 17).  To maintain certification the DRE must maintain a rolling log that demonstrated a minimum 80% accuracy rating when compared with the toxicology results. To be considered an accurate opinion, toxicological confirmation must confirm as follows: for one drug category, the category called must come back positive; for two drug categories, at least one category called must come back positive; for three categories called, at least two categories called must come back positive; the calculation continues in this progression.

You may have had some DUI cases involving drugs come in that you want to beat at trial and may be wondering, how can the State prove whether my client was impaired? Being under the influence of a drug is a subjective experience, a modification of the user’s ordinary experience of consciousness that is only experienced by the individual on drugs. The DRE program has developed “signs and symptoms” which are things that are commonly observed when a person is high on a particular drug. However, since Oregon generally tests urine rather than blood there will be little hard evidence of impairment at the time of driving.

The most common theory of defense in a DRE DUII case is “my client was not under the influence of drugs at the time of driving,” meaning that their physical and mental abilities were not adversely affected to a noticeable or perceptible degree due to the use of a controlled substance. Since Oregon is a urine state there likely will be no hard evidence of impairment at the time of driving. Urine is the waste bin of the body and does not tell the jury anything about impairment at the time of driving. In cases where there was a blood draw did it check for quantity of controlled substance?  Were there other substances in the blood or urine that could also cause the police observations. More on this can be found in the breath, blood, urine chapter of this notebook.

Practice Tip: When discrediting State witnesses with the profoundly unscientific nature of this program be kind. A big part of winning DUI cases at trial is helping the jury like you and your client and helping them not like the police. So many California juries refused to convict possessors of cannabis since the 1960s that they effectively nullified the cannabis part of the controlled substances laws. As J. Tony Serra describes, nullification is the process of transcending the facts of the case, in order to make at least one member of the jury empathize with the plight of the client.

The Seven Drug Categories

The DRE program consolidates all controlled substances into six broad categories and cannabis. The controlled substances listed below are not an exhaustive list but include the substances most commonly seen in Oregon.

  1. CNS Depressants: includes alcohol, barbiturates and benzodiazepines (includes Xanax, Klonopin, Valium and Ativan)
  2. CNS Stimulants: includes methamphetamine, cocaine, Adderall,
  3. Hallucinogens: includes LSD, MDMA, psilocybin, mescaline, DMT, Ayahuasca,
  4. Dissociative Anesthetics: includes ketamine and PCP
  5. Narcotic Analgesics: includes heroin and synthetic opioids. Kratom falls into this category but be aware as of this publication it was not a controlled substance.
  6. Inhalants: includes nitrous oxide and difluoroethane (found in canned air such as Dust-Off).
  7. Cannabis: includes natural THC products and synthetic THC (Marinol)

Some drug categories are called by DREs much more often than others. There were 1,502 DRE evaluations conducted in Oregon in 2018.  Cannabis was the most common call (750), then stimulants (496), then depressants (348), then narcotics (287). Hallucinogens (11), dissociative anesthetics (10) and inhalants (7) were rarely called.

This varies slightly from the national statistics shown in the graph below.  Oregon has a higher percentage of cannabis cases and lower percentage of narcotic cases as shown in the table below.  This table gives a good idea of what police are looking for nationally and in Oregon.

2018 National Totals National Percentage 2018 Oregon Totals Oregon Percentage
CNS Stimulants 8,730 20% 348 18%
CNS Depressants 11,716 26% 496 26%
Hallucinogens 214 0.5% 11 0.5%
Dissociative Anesthetics 554 1% 10 0.5%
Narcotic Analgesics 9,500 21.5% 267 14%
Inhalants 211 0.5% 7 0.5%
Cannabis 13,215 30% 750 40%



We hope that the information contained in this chapter will help you assess and dismantle the state’s case in a DRE DUII. Don’t be intimidated by the scientific nature of the DRE and toxicology report, there are plenty of avenues to attack each piece of the state’s evidence. With persistence and careful attention to details, you can show the jury that a DRE is not sufficient to prove the case.