There has been much discussion about Colorado’s new THC inference of 5 nanograms, but this is not the only device used by prosecutors and law enforcement to secure a conviction for drugged driving. Most police officers with a heavy DUI caseload are being trained in drug recognition. These self-titled “drug recognition evaluators” (DRE) are police officers who are specially trained by local law enforcement in the National Highway Safety Administration’s method of detecting drugged drivers.

A DRE is a law enforcement officer that has completed a training program aimed to sensing and documenting indicia drug impairment. The drug recognition training communicates how to recognize different indications of drug consumption based on seven drug categories: central nervous system depressants; central nervous system stimulants; hallucinogens; dissociative anesthetics; narcotic analgesics; inhalants; and cannabis. Each of these drug categories affect a person differently and has specific indicia that law enforcement officers are taught to look for when a driver is suspected of being under the influence of drugs.

In a typical traffic stop, a motorist may be contacted for speeding or an equipment violation. When contacting the driver at the driver-side window, the patrol officer may suspect drug use because some indicia is present, such as dilated pupils, slurred speech, etc. If the officer suspects that a motorist is under the influence of drugs which impairs or substantially affects the ability to safely drive, the motorist will be arrested for driving under the influence of drugs or impaired by drugs. If the stopping officer does not have training and certification in alcohol and drug recognition, he or she will radio for a drug-recognition evaluator to be sent to the scene or meet the suspect at the closest police substation.

Drug recognition exams are another tool used by the police to detect impaired driving. Comparable to alcohol-related field sobriety tests, like the one-leg stand or the walk and turn test, the DRE exam is designed to give the prosecution evidence to use at trial to convince a judge or jury that a person was under the influence of a drug and this made them unsafe to drive.

The drug-recognition evaluation is voluntary, meaning that the officer must give a proper advisement to a DUI suspect before beginning the process. Required information includes that the exam is voluntary and that the suspect has the right to refuse the test. Unlike a chemical test where blood is drawn and is tested for drug content, there is no administrative or driver’s license punishment for refusing to participate in a drug-recognition exam.

The drug recognition evaluation is a twelve-step protocol for determining if the driver is under the influence of one or more drugs, and what specific category of drug the suspect is under the influence of.  The twelve steps are as follows:

1. BAC Test.  This first step is to determine if the intoxication is caused by alcohol or drugs. If a portable breath test does show the presence of alcohol with a positive reading, the drug evaluation will continue.
2. Interview with the Officer.  The officer will interview the suspect to get info about the appearance, behavior, and driving pattern that led up to the arrest. This interview should always be preceded by a Miranda advisement if the suspect tis in custody, which is likely the case at this stage of the process.
3. Preliminary Examination and First Pulse. This exam involves a sequence of questions regarding the health, food intake, drinking and drug use, including prescription medications. The officer conducting the examination will also witness the arrestee’s appearance, attitude, and coordination.  The pupils will be observed to rule out a neurological disorder or type of brain injury, and the driver’s pulse will be recorded for the first out of three times.  Pulse variations during the evaluation may go toward the stage of the potential impairment.
4. Eye Examination.  There will then be an HGN test done, looking for vertical nystagmus, and lack of convergence. Nystagmus is an involuntary jerking of the eyes that may occur as the eyes move to the side or are elevated, and can be caused by certain drugs.
5. Divided Attention and Psychophysical Tests.  At this point, four roadside tests—the Romberg Balance Test, the Walk and Turn Test, the One Leg Stand Test, and the Finger to Nose Test—are given.
6. Vital Signs and Second Pulse.  Blood pressure, temperature and pulse are again taken.
7. Dark Room Examination.  Both eyes are examined under dark and light conditions to determine if pupils are dilated or constricted.  The DRE also evaluates the eye’s reaction to light.  Finally, the DRE looks for signs of ingestion in the oral and nasal cavities.
8. Muscle Tone.  Certain drug categories cause either rigid or flaccid muscle tone. The officer will evaluate the skeletal muscle tone for rigidity or flaccidity to help recognize which drug categories may be present.
9. Injection Sites and Pulse. The officer will for any track marks or indicia of intravenous drug use and also takes the driver’s pulse again.
10. Driver Statements and Other Observations.  The driver is asked about prior drug use and habit.

Based on the totality of the evaluation, the officer conducting the DRE will make a finding as to as to whether the driver is impaired by drugs and if so, which drug categories are present. The officer will also requests that a sample of the driver’s blood be drawn under Colorado’s Express Consent law and that it be sent to a state certified forensics laboratory for testing.