What is a Drug Recognition Expert?

A Drug Recognition Expert (DRE) is a police officer trained to recognize impairment caused by drug use. A DRE is called upon to evaluate any driver suspected to be under the influence of drugs. They follow a 12-step protocol to determine whether the suspect is impaired, whether the impairment is related to drug use or a combination of alcohol and drugs. If drugs are suspected to be a source of impairment, the DRE will determine what category of drugs may have been consumed.

What tests does a Drug Recognition Expert perform during a Marijuana DUI investigation?

Law enforcement follows 12 steps in the DRE Protocol to determine the presence of marijuana and other drugs during a DUI investigation.

1. Breath Alcohol Test – This preliminary test is conducted by the arresting officer. When a suspect’s impairment is inconsistent with the results of this test, a DRE is called to the scene to perform an investigation to determine other substances that may have lead to intoxication.

2. Interview of the Arresting Officer – When the DRE arrives at the scene, they will review the results of the Breath Alcohol Test with the arresting officer and conduct an interview to learn more about the suspect’s behavior and appearance. The DRE will also ask if the suspect has made statements regarding drug use or if the arresting officer discovered any evidence that may indicate drug use.

3. Preliminary Evaluation and First Pulse Check – In the third step, the DRE will conduct an evaluation to determine if the suspect is suffering from a medical condition or injury that is unrelated to drug use. The suspect is asked questions related to personal health, ingestion of alcohol, drugs, food, and prescription medication. A physical exam is conducted to determine a subject’s mood, coordination, speech, and breath. The DRE will note the size of a subject’s pupils and horizontal gaze nystagmus (HGN), which is a horizontal jerking when the eye gazes from side to side. At this point, the DRE will take the subject’s pulse for the first of three times. This allows the DRE to track for consistency, evaluate nervousness, and determine if the subject’s condition is improving. If the DRE determines that the subject is suffering from a medical condition, medical assistance will be called immediately. If the subject’s condition seems to be drug related, the investigation proceeds to step 4.

4. Eye Examination – This is a more specific test that allows the DRE to determine what type of drug may have been consumed. The test includes Horizontal Gaze Nystagmus, Vertical Gaze Nystagmus, and lack of ocular convergence. Horizontal Gaze Nystagmus, or jerking of the eye when gazing from side to side, may be caused by drugs like inhalants, depressants, and dissociative anesthetics. Vertical Gaze Nystagmus, or jerking of the eye when gazing up and down, may be caused by the same drugs used in higher doses. Lack of ocular convergence, or eyes that are unable to track inward toward the bridge of the nose, may be caused by inhalants, depressants, dissociative anesthetics, or cannabis/marijuana.

5. Divided Attention Psychophysical Tests- These tests determine if a subject’s motor or attention skills are impaired. They include the Romberg Balance Test, The Walk and Turn Test, The One Leg Stand Test, and the Finger-to-Nose Test.

6. Vital Signs and Second Pulse Check – The DRE checks vital signs that include temperature, blood pressure, and pulse.

7. Dark Room Examinations – A device called a pupilometer is used to measure a suspect’s pupil sizes under different lighting conditions and the DRE examines the suspect’s nose and mouth for signs of ingesting drugs.

8. Examination for Muscle Tone – The evaluation of a suspect’s muscle tone determines if they are loose or rigid, which can indicate different types of drug use.

9. Check for Injection Sites and Third Pulse Check – At this point, the DRE will look at common injection sites for evidence of recent drug use. This is also the time of the final pulse check.

10. Subject’s Statements and Other Observations – If the suspect has not been read Miranda rights, the DRE will do so at this time, followed by a series of questions about drug use.

11. Analysis and Opinions of the Evaluator – The DRE determines if a subject is impaired, and what category of drugs may be the cause.

12. Toxicological Examination – As a final step, the DRE will request urine, blood, and/or saliva samples for lab analysis.

How does a Drug Recognition Expert reach their conclusion?

After following the DRE Protocol, the DRE reaches a conclusion based on all facts that emerge during the investigation. The DRE relies on training and experience in the field to determine if a subject is intoxicated and what drugs they may have used. They may also refer to a chart called the DRE Drug Symptomology Matrix to determine if the results are consistent with use of a particular substance.

If you or a loved one are facing charges for Marijuana DUI in California, do not wait to seek legal counsel. Christopher Glew is an expert Marijuana DUI attorney who will provide personal representation in your case to provide the best possible outcome.