Police in Duluth say they've seen a more than 65 percent drop in synthetic drug use in the three months since a head shop that sold the products was shut down.

Police had 495 calls involving synthetics in the 105 days before Last Place on Earth closed in July, the Duluth News Tribune reported Sunday. In the same number of days after the store closed, the number of calls involving synthetics was 160. Store owner Jim Carlson was convicted on 51 charges in early October, including dealing in misbranded drugs. He's seeking a new trial.

Lt. Eric Rish said the "availability and price" offered at Carlson's store made synthetic drug use mushroom. While it still happens, Rish said, the events of the past few months have cut into synthetics' use. Awareness about the dangers of synthetics also has helped.

Police said calls about drunken behavior spiked in the area near the store, but they noted that those drunken disturbances are easier to handle. Mike Tusken, deputy police chief, said disturbances related to synthetics use are "more pronounced and disturbing."

Chris Delp, an emergency room doctor at St. Luke's Hospital, also said he's seen a "huge decrease" in the number of screaming, agitated and psychotic patients, almost from the day Last Place on Earth was closed.

Police Chief Gordon Ramsay posted to Facebook on Oct. 16: "For about the last 20 months I had received a weekly report on all synthetic drug-related police calls with details. For the first time since I have been receiving them, it is less than one full page. Before mid-July it was often 15-20 pages long."

But there are more issues to tackle. Last week, Ramsay said the abuse of heroin and prescription drugs continues to rise in the city.

Deb Holman, an outreach worker for CHUM emergency shelter, said she's seen fewer problems with synthetic drugs, but more work must be done to inform people about their risks. "We need to reach kids in school," she said.

Synthetics are still available in other places, including two shops in Virginia, Minn.

Charles Baribeau, a Virginia City Council member, said there was a "definite influx" of customers after Last Place on Earth closed. A city ordinance that bans the sale and possession of synthetics went into effect there in late October.

After the store in Duluth closed, police noticed that regular customers talked about pooling money to drive to the Iron Range. Some people bought synthetics in bulk and tried reselling them out of a house. Duluth police quickly shut that operation down.

Tusken said Duluth officials did everything they could to get Carlson prosecuted.

"We really didn't have a Plan B," he said. "We put all the chips into the middle of the table."

That patience has paid off, he said. "Jim was brazen," he said. "Saying it was all legal and lucrative. Now people see a consequence."