Drug Recognition Experts how accurate are they?

As illegal prescription drug use soars, the number of cases of driving under the influence in which the substance is a prescription drug rather than alcohol is rising steadily, authorities say.
But prosecuting and obtaining convictions against suspects charged with DUI involving prescription drugs can be a challenge.

Many states, including Florida, do not require a test to quantify the amount of drugs in a person's body in a DUI case, and impairment is difficult to prove.

"What we and other states have run into historically is that there is a well developed system to quantify the amount of alcohol in the human body," said Rob Parker, a Brevard County, Fla., prosecutor.

However, "when you have oxycodone or an opiate, we do not have a well-developed way to quantify the amount of drugs so that a jury can then compare that value to a standard established as an unlawful when operating an automobile."

Law enforcement has limited means to prove impairment. Field sobriety tests are one tool. The state also sometimes relies on drug recognition experts (DREs), police officers who have completed specialized training in detecting impairment due to drugs.

Michelle Perlman, misdemeanor division chief for the Brevard State Attorney's office, said her office recommends law enforcement agencies get a DRE to the scene as soon as possible if a suspected DUI involves drugs.

"This cannot usually be conclusively diagnosed by the average police officer," she said.

There are about a dozen DREs in Brevard, where more than 2,000 people were charged with operating a vehicle under the influence in 2009. As is common around the country, Brevard does not separately track DUIs involving drugs.

Defense Attorney Steve Casanova, who handles scores of local DUI cases, said traces of some drugs can stay in a person's system for as long as 30 days.

"How do you prove it was affecting him at the time of the arrest?" Casanova said.

In other cases, the suspect may have been prescribed the drug legally.


Link:
http://www.usatoday.com/news/nation/2010-10-17-dui-drugs_N.htm?loc=interstitialskip