There is no “Marijuana Breathalyzer” So How Can Police Tell if a Driver is High?

June 25, 2014, 6:30 a.m. ·

Listen To This Story

A police officer easily identifies a drunk driver user a Breathalyzer. It gets more complicated figuring out if someone is under the influence of drugs.


Some researchers feel they are close to creating a reliable, affordable device which detects pot use, but getting it into wide use in patrol cars is years away.

Meanwhile most states, including Nebraska, rely on specially-trained law enforcement officers called drug recognition experts (DRE).

Eighty-nine certified DRE’s currently work for 35 different state and local law enforcement agencies in Nebraska. The specialty is getting added attention as law enforcement anticipates an increase in the number of drivers driving under the influence of marijuana.

A volunteer demonstrates the system used to gauge pupil size during a drug recognition evaluation. (Photo by Bill Kelly, NET News)

“I don’t think there is any doubt that there is a lot of interest now with the increasing abuse of prescription medication and the legalization of marijuana,” according to Fred Zwonechek of the Nebraska Office of Highway Safety. Last week, New York became the 24th state to legalize the use of medical marijuana. In January, Colorado dispensaries started selling recreational pot to both residents and out-of-state visitors.

“We’re going to see people who go across the border who want to entertain their fantasies of being involved in legal marijuana,” Zwonechek said. “Some of them are not going to try and wait until it’s completely out of their system.”

If that prediction is true there may be a need for more drug recognition specialists. Safety advocates argue there is a compelling public safety concern as the acceptance of pot grows. Research released by Columbia University this year suggested between 1999 and 2010 fatal highway accidents involving drivers under the influence of marijuana jumped 300 percent in 6 states studied.

“There are not enough DREs. We could always use more,” said Becky Stinson, the coordinator of the DRE program for the Office of Highway Safety

Currently there are several larger city and county law enforcement agencies that have elected not to cross-train one of their officers in the process. Stinson says while “there are DREs that are available to the majority of all agencies in the state, but it would be to every agency’s advantage to have a DRE.”

Regular patrol officers who suspect, but may not be able to prove with certainty, a driver is under the influence of something other than alcohol have the option of calling a DRE. The evaluation process has similarities to a drunken driving test, but it “takes it a little further” according to Sgt. Mark Bliss of the Scotts Bluff County Sheriff’s Department.

Sgt. Bliss is one of two DRE’s with his department. He also teaches other officers seeking certification.

“Any patrol officer can give a sobriety test. That is what they are trained to do,” Sgt. Bliss said. “However, that training only goes to a certain extent.”

Sgt. Bliss and a volunteer demonstrate one of the coordination tests used in an evaluation. (Photo by Bill Kelly, NET News)

The DRE protocol is designed to figure out if someone is under the influence of one of seven categories of mind-altering drugs. It will not specify methamphetamine, cocaine, or marijuana, but can identify behavioral and physiological signs that point to their use.

“I may say this person is under the influence of a central nervous system stimulant or a central nervous system depressant or when we are talking about cannabis, all of the marijuana products, which is like your hashish, your hash oil,” Bliss said.

Marijuana was the drug impairing drivers in more than half of the DRE evaluations done by trained officers in Nebraska since 2009.

There are twelve steps in the nationally recognized drug recognition evaluations used by law enforcement. Some of the tests given the suspect are similar to the well-known field sobriety test given at drunken driving check points. Officers ask the subject to close their eyes and touch their nose, albeit in a very specific manner. The ability to judge time is gauged by simply estimating when 30 seconds have passed. Someone using meth may say the time is up in just 15 seconds. Others using marijuana have gone as long as a minute and a half.

Examining the size of pupils and how well the individual can control eye movement are important elements of the process. “When you use cannabis you aren’t going to be able to cross your eyes," Sgt. Bliss said. “The eyes will be drifting off.”

Blood pressure, muscle response, notes from interviews, and finally a urine test round out the twelve steps every evaluation is supposed to include. Over the past five years it’s been a process repeated more than 2,000 times in Nebraska. (Read a detailed description of the process here.)

The interviews and tests are typically done at a police station or sheriff’s office and are recorded so they can be used as evidence in court if needed. Indoor locations also help make sure the process is consistent and without interference from any number of factors that could undermine the validity of the tests.

“It has to be in a controlled environment,” Bliss said. “We take the person out of the snow, the rain, the wind, the gravel road so it’s a controlled environment.”

A well-done evaluation should be able to withstand a challenge in court. Nebraska was an early adopter of the DRE program in the early 1980s. Since that time a number of academic studies have shown the tests, properly done, are an accurate method of determining if some is under the influence of a mind-altering drug.

“It’s accurate. It’s working,” Sgt. Bliss said. “It’s not voodoo science.”

Nebraska judges consistently reject appeals from drivers challenging the legality and accuracy of the tests. The Nebraska Supreme Court has backed them up on appeal.

Jacob Daly got busted by police in Lincoln for driving under the influence of marijuana and a jury found him guilty. In 2009, he appealed to the state’s highest court, arguing, among other things, parts of the DRE evaluation were flawed. The justices ruled against him pointing out that having twelve steps allows an officer to not make a judgment based on a single factor but forming “an opinion based upon all of the relevant observations” making it “reliable enough to be admissible” in court. Daly asked if that met a high enough standard to be used as evidence and the Supreme Court wrote “the scientific literature supports the conclusion that it is.” (Read State of Nebraska v. Jacob Daly)

North Platte-based Attorney Russel Jones has defended clients arrested after their DUI drug test. “Those tests are very good tests if they are given properly and scored properly,” Jones said.

He finds the testimony of drug recognition experts difficult, but not impossible, to challenge. The rigorous standardized methods used by the officers can provide someone accused of driving while high an opportunity to raise a reasonable doubt about the accuracy of the judgment made as a result of the evaluation.

“Deviating from the system obviously makes their case weaker based on the fact that the test doesn’t necessarily mean anything if it’s not given the right way,” Jones said.

Eighty-nine trained and certified drug recognition experts cover the entire state. Some federal grant dollars administered by the Nebraska Department of Highway Safety pay for training and equipment for officers wishing to get the certification. Even with that help some larger police and sheriff’s departments don’t have any of the experts on their force. Some don’t want to take an officer off the streets for days of required classes.

The evaluations are not just a tool to prosecute someone, according to Stinson of the Office of Highway Safety. “It’s much greater than that.

"It’s about me and my loved ones driving around on the roads with people who are choosing to do the wrong thing,” Stinson said. “It is a way to combat that problem.”