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Drug Recognition Expert (DRE)

Drug Recognition Expert Evaluation

Challenging Incriminating Evidence

  • If you are pulled over on suspicion of driving under the influence of marijuana or drugs, the arresting officer, or another officer trained as a DRE (Drug Recognition Expert), will try to get you to agree to submit to a 12-step evaluation that can take up to an hour.
  • The officer must complete all 12 steps in order for his or her “expert” testimony about the evaluation to be admissible. This evaluation is completely optional and currently there are no penalties for refusing to do the DRE Evaluation. Therefore, you should decline the evaluation as politely as you can.

Gathering Evidence Against You

During this evaluation, the officer, who is not a physician, pharmacologist, toxicologist, ophthalmologist, or even an EMT, will perform a series of tests including:

  • A physical exam of your blood pressure, pulse, muscle tone, temperature, etc.
  • An eye exam in a nearly dark room to test your eyes’ reaction to light, nystagmus, and pupil size
  • Physical balance and divided attention tests, like tilting your head back and counting (in your head) to 30 seconds
  • Questioning about your day and what you did/took before being arrested

Officers trained as DRE’s will look at all the clues they find in each of these steps to attempt to figure out what drug type, if any, is affecting you and if you are indeed impaired. After this evaluation, or if you decline the evaluation, you will be asked to submit to a test of your blood. If you agree, you will be taken to a nearby hospital, or an aid car with EMTs may be called to the scene in order to do a blood draw.

Marijuana and Drug Recognition expert Evaluation

Linda M. Callahan

HGN - Eye Test

  • When an officer does a DRE Evaluation for suspicion of marijuana or drug use, they will look for a number of clues indicating impairment. One of the clues of marijuana use is a lack of Horizontal or Vertical Gaze Nystagmus (HGN/VGN), which is an involuntary “bouncing” of the eye when looking to the side, up, or down that indicates alcohol consumption or consumption of a central nervous system depressant.
  • Instead, the eyes of a person who has consumed marijuana may lack convergence—meaning the individual is unable to move both eyes toward the center (their nose bridge) at the same time

Other Clues

  • Another clue for marijuana is elevated pulse and blood pressure. Typically, there will also be a distorted perception of time, so counting to 30 seconds accurately can be difficult. Since these clues may also indicate various other drug types, DRE officers are trained to make their assessments based on the totality of clues that they find.
  • DRE officers must keep a “rolling log” of all of their DRE evaluations in order to keep their certification as a DRE. The log keeps track of how well the DRE is able to correctly identify the category of drug used, as validated or invalidated by the blood analysis.

“Tough DUI Laws Require Tough DUI Lawyers”

Linda M. Callahan

plan of action

know your rights

Washington State has some of the toughest DUI laws in our nation. These laws carry increasingly severe penalties for those who drink and drive. Washington lowered the BAC limit from .10 to 0.08 in January of 1999. Drivers with a blood-alcohol concentration (BAC) at .08 or above can now be convicted of driving under the influence of alcohol. In addition, because public sentiment is so very negative toward drunk drivers, prosecutors will often pursue a DUI conviction even when the driver’s test result is well under .08! This is possible because they can obtain a conviction if they can show the person drove while “affected by” alcohol, and/or marijuana or any drug, including prescription or over-the-counter medications.

We Challenge The Following Evidence On Every Case.


Probable Cause

Before you were asked to step out of your vehicle, the officer has been gathering evidence to support the arrest.


Field Sobriety Tests

As Ms. Callahan likes to call them “Bad Science”, FST’s are virtually impossible to pass, especially if the officer is the one grading you.


Breath Test - BAC

Factory trained, Linda M. Callahan understands the science behind breath testing most attorneys don’t.


Blood Test

With extensive training at Axion Labs in Chicago, Linda M. Callahan has the relevant experience to challenge Blood test evidence.

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Snohomish County DUI Attorney

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