Pupillometers help police spot pot-using drivers

CLACKAMAS CO., Ore. (KOIN) — It’s been 5 months since the sale and use of recreational marijuana became legal in Oregon, and since then, local deputies say they’ve seen higher rates of impaired driving.

Now, Oregon State Police is increasing its training procedures for officers across the state to help them spot and apprehend drivers who may be under the influence of marijuana.

Sgt. Jason Ritter with Clackamas County Sheriff’s Office says drivers sometimes show signs of paranoia, hallucinations and delayed perceptions of time and distance.

He uses a pupillometer to look for dilated eyes.

“I’m looking for… the glow of the eye so I can measure the pupil,” Sgt. Ritter said.

Pupil dilation can be measured in 3 ways:

1. Room light
2. Direct light
3. Near complete darkness

The test helps determine if a driver is impaired and what drugs they may have used.

But before the test is done, deputies perform standard field sobriety tests. They look for signs of impairment at the same time. For pot, there are specific indicators.

Some signs are “altered perception of time and distance, body tremors, eyelid tremors, bloodshot eyes.” If they fail, they are often arrested and taken to the station.

From there, deputies will administer a breath test.

“If the level of impairment is not consistent with the BAC level that I observed, a Drug Recognition Expert (DRE) is called in to come do a drug evaluation,” Sgt. Ritter said.

DREs follow a 12-step process to assess their suspects.

1. Breath Alcohol Test
2. Interview of the Arresting Officer
3. Preliminary Examination and First Pulse
4. Eye Examination
5. Divided Attention Psychophysical Tests
6. Vital Signs and Second Pulse
7. Dark Room Examinations
8. Examination for Muscle Tone
9. Check for Injection Sites and Third Pulse
10. Subject’s Statements and Other Observations
11. Analysis and Opinions of the Evaluator
12. Toxicological Examination

From there, DRE protocol usually calls for a urine, blood or saliva test.

Charges can be filed if the suspect is found to be impaired.