Police officers from across Maine gathered at the Criminal Justice Academy in Vassalboro Wednesday as part of a training to become Drug Recognition Experts.

Senior DRE instructor Robert Libby, a detective at the South Portland Police Department, said that the state needs more DREs because recreational marijuana is now legal. Libby believes that more people could choose to drive impaired with easier access to the drug.

"People making poor choices -- and innocent people are the ones that pay the heavy price, and I just want to make sure I keep the roads safe," said Libby.

Libby said people are "poly-drug using," meaning they use more than one drug at a time.

"Not only are we talking about marijuana, but we also have a narcotic drug issue going on," said Libby.

DREs learn how to identify how all kinds of drugs exhibit different effects in the human body.

After determining that the presenting symptoms are truly impairment and not a medical issue, officers will move forward with administering the field sobriety tests.

"Drug impairment is a lot different than alcohol," said Brian McNeice, an officer with the York Police Department. "A lot of [this training] has to do with signs and symptoms with the body, and there's more of a medical aspect to it."

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The MCJA used to hold this training once every two years, but now conducts it every year. There are about 90 DREs for the entire state of Maine, but Libby said they need more.

Police in rural areas or smaller departments can sometimes not afford the cost of the training, funded by the Maine Bureau of Highway Safety. That means officers sometimes have to request a DRE from a nearby department, but that can sometimes take time for the DRE to travel to the scene, and the driver's impairment my exhibit itself differently by the time the DRE arrives, according to Libby.

Officers hope this training will help keep the public safe.

"I just hope it can make me better at detecting impaired drivers -- getting impaired drivers off the road," said McNeice.