Dude, Who’s To Say I’m Stoned?

Are the signs of marijuana intoxication so familiar to the public that prosecutors can rely on the observations of police in stoned driving cases, or are experts required?

That’s a question the state’s highest court is considering, hearing arguments Friday in the case of Thomas Gerhardt, who was charged with driving under the influence of drugs after a February 2013 traffic stop off Route 146.

“Like alcohol, marijuana usage at this point is so widespread — it is in the common experience of a juror — that an expert is not required,” Worcester prosecutor Michelle King argued before the Supreme Judicial Court.

Public defender Rebecca Jacobstein argued experts are necessary witnesses at trial to explain a police officer’s observations of an allegedly stoned driver, and said roadside impairment tests used to identify drunk drivers are not suitable to detect marijuana intoxication.

“There are no physical characteristics that permit an inference of impaired driving due to marijuana use, and a layperson does not have sufficient understanding of marijuana’s physical manifestations,” Jacobstein told the justices.

“What if he stumbles and he says, ‘Oh my goodness, I just had five joints,'” said Justice David Lowy. “Do you need an expert?”

“You still do,” Jacobstein replied.

More