MISSOULA, Mont. — A judge dismissed a marijuana possession charge filed against a Florence-Carlton High School student after a drug dog searched the school parking lot, a decision that could lead to changes in the way schools enforce their drug-free policies.

District Judge James Haynes of Hamilton ruled the Dec. 17, 2015, search was illegal because school officials did not have a reasonable suspicion to conduct the search, the Missoulian reported (http://bit.ly/2egyWgT).

Haynes said the search could have been considered legal if there was a significant problem with drugs at the school or if school officials had specific information indicating student had drugs.

“Unfortunately, there exists no evidence in the record in this case before the Court that the school district’s formal search policy is anything other than a proactive good idea,” Haynes wrote in his Oct. 6 ruling.

The student’s attorney, Minot Maser, argued: “You can’t just do dragnet searches without an individual cause or a bigger drug issue.”

Missoula attorney Elizabeth Kaleva, who represents school districts across the state, said that while Haynes’ ruling is binding only in Ravalli County, she’s telling the schools districts she represents to avoid using drug dogs for now.

“What the court is saying is, ‘You need reasonable suspicion to even use the dog,'” Kaleva said. “I’ve told them I don’t believe it’s right to use them at this time.”

Haynes also suppressed evidence that marijuana was seized from the teen 10 days earlier. Maser argued a sheriff’s deputy had no reason to be suspicious when he saw the 16-year-old sitting in a car in a Florence neighborhood late at night. Haynes said there was no evidence the student had committed or was about to commit a crime.

Information from: Missoulian, http://www.missoulian.com