On January 31 of this year, the Vermont State Police received a call from a 49-year-old woman who reported that she was being followed by a man driving an SUV with Massachusetts plates. Troopers stopped the suspect on Route 30 in Townshend and discovered that the vehicle had been reported stolen.

During the roadside stop, the trooper suspected that the driver, 46-year-old Kurt Konig of Gloucester, Mass., was buzzed — and not on booze. Konig was subsequently arrested and charged with operating a vehicle under the influence of drugs.

Under Vermont's impaired-driver law, a driver can be charged with a DUI if his or her blood alcohol content is at or above 0.08 percent. But when it comes to legal intoxicants, such as pharmaceuticals—and illegal ones, such as heroin, cocaine, marijuana and LSD—no Breathalyzer, blood test or urinalysis can determine conclusively whether the driver is too high to drive. It's a problem Colorado and Washington State wrestled with after they legalized weed.

How do cops decide when to charge someone with drugged driving?

Simple: They use a 12-step process. No, not the 12-step program of Alcoholics Anonymous, but a dozen physical tests, observations and clinical examinations performed by a drug recognition expert. DREs — of whom there are 35 statewide, including 17 in the Vermont State Police — are police officers trained to recognize the signs of a driver impaired by substances other than alcohol.

So are cops looking for uncontrollable giggling, overconsumption of salty snacks or an undue fascination with shiny objects? WTF?

Nothing of the kind, says Brad Vail, deputy chief of the Hartford Police Department and one of Vermont's three DRE trainers. As Vail explains, a driver suspected of being high is first given the standard field-sobriety test used on all suspected impaired drivers. This test checks a driver's basic cognitive and motor skills, such as the ability to walk a straight line, stand on one foot, touch one's nose and follow officers' instructions accurately. It also includes the horizontal-gaze nystagmus test, or "pencil test," which detects involuntary eye movements.

If a driver bombs those tests but the Breathalyzer comes back negative, Vail says, the suspect can be taken to a police station, barracks or emergency room (in the event of an accident). There a DRE checks clinical indicators such as blood pressure, pulse and pupil dilation in various light levels.

The goal, Vail says, is to "connect the dots to put together a bigger picture." That picture includes any of seven categories of drugs the person may have ingested: depressants (including barbiturates and tranquilizers such as Xanax and Prozac); stimulants (amphetamines, crack, crystal meth); hallucinogens (acid, mushrooms, ecstasy); dissociative anesthetics (ketamine, PCP); narcotic analgesics (heroin, morphine, OxyContin); inhalants (paint thinner, hair spray, glue); or cannabis (weed, hash). Later, a toxicology screen can confirm evidence of those drugs.

Vail notes that a DRE can also determine whether the driver is sober or impaired for medical reasons. In fact, one day before being interviewed for this story, Vail was called to the VA Medical Center in White River Junction to evaluate a suspected drugged driver. A subsequent CT scan revealed his impairment was due to a previously unknown brain tumor.

Are DRE findings admissible in court? Definitely, says Sgt. James Roy of the Colchester Police Department, who oversees all DRE training statewide. Roy, who is often asked to testify in drugged-driving prosecutions, says that neither the Vermont Supreme Court nor the U.S. Supreme Court has ever heard a challenge to the DRE procedure. It's been ruled as admissible evidence by judges in five Vermont counties.

But is the underlying science valid? Not very, charges Brooks McArthur. The Burlington defense attorney is currently representing Fata Sakoc, a woman who's suing a former state trooper for allegedly taking her into custody under false pretenses.

According to court papers, on March 5, 2010, Sakoc was stopped for driving erratically, then arrested and charged with a DUI based on the testimony of a South Burlington DRE. Although the trooper found no evidence of drugs or paraphernalia (e.g., syringes, pipes, spoons, track marks, the odor of weed) on Sakoc or in her car, the DRE determined that she was under the influence of an unspecified "central nervous system depressant."

A subsequent blood test, which screened for the presence of more than 100 drugs and their metabolites, turned up no illegal substances. In fact, the only "intoxicants" found in Sakoc's blood were traces of nicotine, caffeine and chocolate.

Sakoc's civil rights lawsuit, filed in U.S. District Court in Burlington, charges that "there are no scientific, medical or pharmacological standards underlying the DRE program," and that its findings are based solely on subjective opinion, not objective measurements.

Roy says he's heard those criticisms before. While he acknowledges there are no peer-reviewed studies of the DRE process, he points out that the program has stood the test of time since its development by the Los Angeles Police Department in the 1970s. (Vermont started using DREs in 2008.)

"Judges across the United States, over and over and over, resoundingly say it's useful information," Roy says, "and it's capable of doing what it claims to do."

Whether the DREs' tests are real or junk science, one fact is irrefutable: Vermont police increasingly rely on them to ferret out drugged drivers. According to the Vermont Governor's Highway Safety Program, of the 71 fatalities on Vermont roads in 2013, 10 involved drivers under the influence of just alcohol. Seven involved drivers under the influence of drugs only, and eight involved drivers under the influence of both.

Talk about a buzz killer.

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