Vermont’s ‘Drug Recognition Experts’ Are Met With Skepticism

Valley News Staff Writer
Published: 9/15/2018 11:18:59 PM
Modified: 9/15/2018 11:19:00 PM

White River Junction — Defense attorneys in Vermont are questioning the reliability of a method police officers use to test for drug impairment when drivers appear to be operating under the influence of some sort of substance but have little to no alcohol in their system.

The system relies on specially trained officers, known as “drug recognition experts,” or DREs, who use a “standardized and systematic method” that takes observable signs and symptoms that are known to indicate drug impairment and matches them with the signs and symptoms a suspect is exhibiting, said Vermont State Police Lt. John Flannigan, who is the state coordinator for the International Drug Evaluation and Classification Program.

Unlike with alcohol, for which states have established quantitative measures that signal what amount of alcohol constitutes legal impairment, no such standards exist for other substances. The lack of such tests may become particularly contentious now that Vermont and other states have legalized the recreational use of marijuana.

The 12-step process used by DREs starts by ruling in or out the presence of alcohol through a standard breath test, and then shifts to a series of examinations, which include eye tests and vital signs checks. The DRE officer interviews the suspect about his or her drug use and ultimately issues an analysis and opinion on whether the person is impaired and by what substance or substances.

Several defense attorneys this week questioned the reliability of that test, saying it lacks scientific validation through peer reviews and other studies.

“This DRE stuff has not been proven to be reliable by the scientific process that is accepted in every other important avenue,” Norwich-based attorney George Ostler said.

Other attorneys agree.

“What they have done is try to create experts with this veneer of science that in essence do what we wanted to move away from 40 years ago,” said St. Johnsbury-based attorney David Sleigh, who recalled a day when prosecutors called doctors to opine on whether someone was driving under the influence of alcohol. “That evolved into a preference of relatively objective scientific testing.”

“To me, this is a return to the bad old days,” Sleigh said.

Despite attorneys’ skepticism, Flannigan stands by the testing method, which started in the 1970s, is used in all 50 states and Canada, and has the endorsement of the National Highway Traffic Safety Administration.

“It is recognized in the science community as using scientific methods and principles, and it’s the course across the country,” Flannigan said.

In addition, the Vermont Medical Society endorses the program, saying the protocols “are based on valid and reliable procedures,” according to a 2017 letter written by then-Executive Vice President Paul Harrington. “(The) program provides law enforcement officers with specialized training to evaluate, and when necessary, determine whether or not drivers may be impaired while operating a motor vehicle, watercraft or recreational vehicle under the influence of drugs in addition to, or independent of, alcohol.”

Training and Application

All DREs must first be certified police officers and have completed standard field sobriety testing. Vermont Police Academy graduates who completed training after 2015 also must finish within three years of graduating the Advanced Roadside Impaired Driving Enforcement program, which is one step below the training an officer receives in the DRE program, said Hartford Deputy Police Chief Brad Vail, who was one of the first DREs in the state.

Vermont has had DRE officers since 2005.

DRE training includes 72 hours of classroom instruction and the completion of at least 12 drug evaluations under the supervision of a trained DRE instructor.

Just completing the exams isn’t sufficient either.

“The officer must identify an individual under the influence of at least three of the seven drug categories and obtain a minimum of 75 percent toxicology corroboration rate,” according to the International Drug Evaluation and Classification Program’s website, which falls under the International Association of Chiefs of Police.

The seven categories lump together drugs that can have similar effects on a person’s body, factors that could help an officer conclude what drug a person is under the influence of. The categories are: central nervous system depressants, central nervous system stimulants, hallucinogens, dissociative anesthetics (PCP, for example), narcotic analgesics, inhalants and marijuana.

As an example, a stimulant, such as cocaine, would increase a person’s heart rate and elevate his or her blood pressure, according to the program’s website.

After an officer makes a traffic stop and determines that a person may be impaired by a substance other than, or in addition to, alcohol, a DRE is called to the station — or to a hospital, in the event of serious injury — to conduct a test. The tests are not conducted roadside.

According to the program’s website, each evaluation involves the following 12 steps:

■A breath alcohol test to determine if the person is impaired by alcohol.

■An interview of the arresting officer to inform the DRE about the arrested person’s behavior and appearance during the traffic stop.

■A preliminary examination and first pulse test, to figure out if the person may be suffering from an injury or medical condition not related to drugs, in which case the officer would seek medical help.

■An eye examination for involuntary jerking of the eye, a symptom that might indicate drug use.

■Psychophysical tests, including the walk and turn, one-leg stand and finger-to-nose tests.

■Vital signs and second pulse, including a reading of the person’s blood pressure and temperature.

■A re-examination of the person’s eyes under three different lighting conditions to examine pupil size, which can be an indicator of a certain category or class of drugs.

■An examination of a person’s muscle tone, because drugs can make muscles rigid or flaccid.

■A check for injection sites and a third pulse reading.

■An interview with the person about his or her drug use.

■The writing of an analysis and opinion about whether a person is impaired, including the drugs that may be involved.

■A request that the person consent to a blood draw, or toxicology test, if the officer thinks there is impairment. If the person don’t consent, the officer can seek a search warrant that would compel the procedure.

The evidence obtained during the test — even absent a blood draw — is sufficient to bring charges, Flannigan said.

If an officer has probable cause to believe a person is impaired by drugs, the officer seeks a toxicology test, which typically takes two to three weeks to get back, Flannigan said. The idea is the toxicology test will corroborate the DRE test.

“More evidence is better than less evidence,” he said.

Past Results

In 2017, Vermont Drug Recognition Experts evaluated 263 people, and of those, the DREs concluded that 158 people were impaired by marijuana, according to a 2017 report commissioned by the International Association of Chiefs of Police.

Of the 263 people who were pulled over, the officers concluded 22 times that the driver wasn’t impaired.

On eight occasions, the toxicology results came back negative for drugs. That doesn’t mean that an officer got the impairment portion of the test wrong, though, Flannigan said.

A negative blood test, for example, could result from a new synthetic drug that wouldn’t show up in a drug screen, or it could be that a person may have drugs in his or her system that fall below the cutoff level for detection in a toxicology test, he said.

The number of evaluations increased by more than 12 percent in 2017 from the previous year, according to the report.

The idea for the DRE program started in the 1970s when Los Angeles Police Department members came to the conclusion that people who had zero or low blood alcohol concentrations still were exhibiting signs of impairment. In response to that, two officers got together with medical professionals to develop a procedure for recognizing drug impairment. That lead to a standardized DRE protocol, according to the program’s website.

There now are 50 DREs in Vermont, and nine more officers are slated to graduate with the training by the end of the month, something that could help reduce the wait time when a DRE is needed, Flannigan said.

Time is important, said Windsor County State’s Attorney David Cahill, who noted that “insight into the person’s current impairment level is key, because a blood test is often two to three hours away and the compounds that cause impairment can, in many cases, disappear from the bloodstream during that time.”

Recreational marijuana use became legal in Vermont on July 1 — too soon to determine if there has been an increase in marijuana-impaired driving, Flannigan said.

Across the river in New Hampshire, recreational marijuana use remains illegal, as it does on a federal level.

New Hampshire also uses drug recognition experts and has 89 certified officers.


The DRE test is reliable when a person under questioning tells an officer that he or she is under the influence of a certain drug and the officer checks that box, said attorneys Dan Davis, of Brattleboro, and Chris Dall, of Norwich.

But when the officer isn’t given that information or doesn’t find drug evidence on the person or in the vehicle, the accuracy of the test is questionable, the attorneys said.

“When you don’t have that self-reporting, I am not certain that this is a reliable form of testing,” said Davis, who is a former Vermont State Police trooper and a former lead prosecutor in Windham County.

Davis, Dall, Sleigh and Ostler called for more “patience” and “serious scientific work” before continuing to use this method.

“In criminal court, there is tremendous pressure to convict people and this dubious science emerges from time to time,” Ostler said. “Right now, especially with marijuana legalization, there is a rush to try to figure out what kind of evidence can be used against people, especially those who have been driving after smoking marijuana.”

In addition, and if possible, Sleigh said, someone should establish limits that could illustrate marijuana impairment, much like the .08 blood alcohol content threshold.

“Absent that, anything you have will not live up to the goal of having reliable objective evidence,” Sleigh said.

Just what those limits should be are unclear to Davis, who said that is just another reason more research should be conducted.

In Colorado, where recreational marijuana also is legal, lawmakers have set a limit: if people drive with 5 nanograms of active THC in their blood, they can be prosecuted for driving under the influence. Despite this, “no matter the level of THC, law enforcement officers base arrests on observed impairment,” according to Colorado’s state website.

Davis said Colorado “pulled (that) number out of thin air.”

Asked why Vermont hasn’t set a limit, Vermont State Police’s Flannigan said: “There is no scientific basis for setting a specific limit or active THC at this time.”

Flannigan said that although the “per se” alcohol impairment limit in Vermont is .08 — meaning anyone who is determined to have that amount of alcohol in his or her bloodstream is, by definition, legally impaired — there also is “impairment to the slightest degree,” meaning a driver can be found to be impaired even if his blood alcohol content tests below that threshold.

Although there is “no limit standard for any drug in Vermont ... the slightest degree standard also applies to drugs,” he said.

“Levels don’t necessarily equal (or not equal) impairment and the state has to prove that the drug(s) impaired the operator to the slightest degree,” Flannigan said. “This is based on the totality of circumstances and evidence, such as driving behaviors, sobriety tests, DRE examination and other evidence presented with the facts.”

Cahill, the prosecutor, said people must “accept the DRE program for what it is.”

“It does not magically convert a police officer into a forensic toxicologist,” he said. “However, it allows a police officer to apply standardized procedures and generally accepted scientific principles to determine whether a person is currently experiencing the effects of a drug.”

Flannigan contends the DRE testing has been proved in at least two arenas.

“The reliability of the evaluation process has been challenged thousands of times and has been upheld by the courts in Daubert or Frye hearings,” Flannigan said. “Same for the science community, as there have been many studies, such as Johns Hopkins (1980s), LAPD and the recent 302 study that examined Cannabis-specific evaluations.”

Ostler said he has won cases or had cases that weren’t prosecuted because he could prove that the DRE test wasn’t reliable.

For example, he said, he has had a case where the DRE said the person exhibited signs of impairment that detected both depressant and stimulant drugs. Those classes of drugs would have opposite effects on a person’s body, Ostler said.

“It is our job to make sure evidence that is presented in court is reliable,” Ostler said. “This stuff isn’t.”

Jordan Cuddemi can be reached at or 603-727-3248.

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