The DRE protocol is a standardized and systematic method of examining a Driving Under the Influence of Drugs (DUID) suspect to determine the following: (1) whether or not the suspect is impaired; if so, (2) whether the impairment relates to drugs or a medical condition; and if drugs, (3) what category or combination of categories of drugs are the likely cause of the impairment. The process is systematic because it is based on a complete set of observable signs and symptoms that are known to be reliable indicators of drug impairment.
A DRE never reaches a conclusion based on any one element of the evaluation, but instead on the totality of facts that emerge. The DRE evaluation is standardized because it is conducted the same way, by every drug recognition expert, for every suspect whenever possible. Standardization is important because it makes the officers to be better observers, helps to avoid errors, and promotes professionalism.
The 12-Step DRE Protocol
The DREs utilize a 12-step process to assess their suspects:
1. Breath Alcohol Test
The arresting officer reviews the subject’s breath alcohol concentration (BrAC) test results and determines if the subject’s apparent impairment is consistent with the subject’s BrAC. If so, the officer will not normally call a DRE. If the impairment is not explained by the BrAC, the officer requests a DRE evaluation.
2. Interview of the Arresting Officer
The DRE begins the investigation by reviewing the BrAC test results and discussing the circumstances of the arrest with the arresting officer. The DRE asks about the subject’s behavior, appearance, and driving. The DRE also asks if the subject made any statements regarding drug use and if the arresting officer(s) found any other relevant evidence consistent with drug use.
3. Preliminary Examination and First Pulse
The DRE conducts a preliminary examination, in large part, to ascertain whether the subject may be suffering from an injury or other condition unrelated to drugs. Accordingly, the DRE asks the subject a series of standard questions relating to the subject’s health and recent ingestion of food, alcohol and drugs, including prescribed medications. The DRE observes the subject’s attitude, coordination, speech, breath and face. The DRE also determines if the subject’s pupils are of equal size and if the subject’s eyes can follow a moving stimulus and track equally. The DRE also looks for horizontal gaze nystagmus (HGN) and takes the subject’s pulse for the first of three times. The DRE takes each subject’s pulse three times to account for nervousness, check for consistency and determine if the subject is getting worse or better. If the DRE believes that the subject may be suffering from a significant medical condition, the DRE will seek medical assistance immediately. If the DRE believes that the subject’s condition is drug-related, the evaluation continues.
4. Eye Examination
The DRE examines the subject for HGN, vertical gaze Nystagmus (VGN) and a for a lack of ocular convergence. A subject lacks convergence if his eyes are unable to converge toward the bridge of his nose when a stimulus is moved inward. Depressants, inhalants, and dissociative anesthetics, the so-called "DID drugs", may cause HGN. In addition, the DID drugs may cause VGN when taken in higher doses for that individual. The DID drugs, as well as cannabis (marijuana), may also cause a lack of convergence.
5. Divided Attention Psychophysical Tests
The DRE administers four psychophysical tests: the Romberg Balance, the Walk and Turn, the One Leg Stand, and the Finger to Nose tests. The DRE can accurately determine if a subject’s psychomotor and/or divided attention skills are impaired by administering these tests.
6. Vital Signs and Second Pulse
The DRE takes the subject’s blood pressure, temperature and pulse. Some drug categories may elevate the vital signs. Others may lower them. Vital signs provide valuable evidence of the presence and influence of a variety of drugs.
7. Dark Room Examinations
The DRE estimates the subject’s pupil sizes under three different lighting conditions with a measuring device called a pupilometer. The device will assist the DRE in determining whether the subject’s pupils are dilated, constricted, or normal. Some drugs increase pupil size (dilate), while others may decrease (constrict) pupil size. The DRE also checks for the eyes’ reaction to light. Certain drugs may slow the eyes’ reaction to light. Finally, the DRE examines the subject’s nasal and oral cavities for signs of drug ingestion.
8. Examination for Muscle Tone
The DRE examines the subject’s skeletal muscle tone. Certain categories of drugs may cause the muscles to become rigid. Other categories may cause the muscles to become very loose and flaccid.
9. Check for Injection Sites and Third Pulse
The DRE examines the subject for injection sites, which may indicate recent use of certain types of drugs. The DRE also takes the subject’s pulse for the third and final time.
10. Subject’s Statements and Other Observations
The DRE typically reads Miranda, if not done so previously, and asks the subject a series of questions regarding the subject’s drug use.
11. Analysis and Opinions of the Evaluator
Based on the totality of the evaluation, the DRE forms an opinion as to whether or not the subject is impaired. If the DRE determines that the subject is impaired, the DRE will indicate what category or categories of drugs may have contributed to the subject’s impairment. The DRE bases these conclusions on his training and experience and the DRE Drug Symptomatology Matrix. While DREs use the drug matrix, they also rely heavily on their general training and experience.
12. Toxicological Examination
After completing the evaluation, the DRE normally requests a urine, blood and/or saliva sample from the subject for a toxicology lab analysis.Nothing in or about the DRE protocol is new or novel. The DRE protocol is a compilation of tests that physicians have used for decades to identify and assess alcohol- and/or drug-induced impairment.