AUGUSTA — Leaving a 100-plus-year-old badge with the Augusta Police Department wasn’t Keith Bushey’s plan when he came to the city to offer weeklong training to dozens of officers from across Maine.

Bushey, an instructor with the FBI Law Enforcement Executive Development Association, has one of the largest badge collections in the nation in his California home.

Bushey brought the city marshal badge with him to Augusta to see if he could find a picture of someone wearing it. He planned to take it with him when he left, but that changed when he saw the department’s museum and commitment to knowing and honoring its history.

“The badge started to talk to me,” Bushey said. “The badge said, ‘Don’t you dare take me out of Augusta again.’ There was no way, in good conscience, I could take that badge back to California.”

Augusta police Sgt. Christian Behr, who has spent more than a year compiling the department’s history, said the badge will be added to the growing inventory of artifacts in the department’s museum.

“Out of the blue, a former officer from California is here in Augusta, Maine, instructing a leadership class to our police officers, and he brings along a piece of our history and returns it home out of the goodness of his heart,” Behr said. “I’m almost speechless about that.”

The badge, which eventually came to be known as a radiator badge because of its resemblance to the radiator of a Ford Model T car, was worn by the city marshal, the forerunner to the chief of police. Bushey, whose knowledge of badges has earned him an appearance on the television series “Storage Wars,” said the badge style was prominent in New England in the last part of the 1800s.

“If that badge could talk, it would tell some stories,” Bushey said.

The Augusta police collection includes photos from 1907 of the six men who made up the department at the time. One of the men in the picture, believed to be City Marshal Dennis Donovan, is wearing a marshal’s badge. Donovan was marshal from 1906 to 1907.

Augusta Police Chief Robert Gregoire said the badge is most likely handmade.

“Most of those badges were made individually,” he said. “They weren’t very common.”

The men believe the badge Bushey gave to the department is the same badge worn by Donovan in the picture.

“Marshal Donovan’s badge has finally come home,” Bushey said.

The badge will take its place with three others donated to the department in recent years. One of those badges dates to the 1850s. Another, a cap badge, dates to the 1920s.

“We now have actually bridged the gap,” Behr said.

Bushey said he bought the badge from a collector in Las Vegas. It’s anyone’s guess how the badge wound up there.

“The badge traveled around the country a little bit, but we’ve got it back now,” Behr said.

Gregoire asked Behr to research the department’s history after a local family donated a pair of badges to the department, including a handmade copper badge dating to the 1850s.

At the time, the department wasn’t even sure when it was founded. Behr has since learned the first marshal was sworn in on March 27, 1850. The department will celebrate its 165th anniversary later this month.

The history project turned into a passion for Behr, who has compiled a history that includes articles, artifacts and anecdotes. Behr said he reminds new officers of the department’s history when they join the force.

“Water Street has always been Water Street,” Behr said. “Somebody could come back to Water Street 200 years later and say, ‘This looks the same, except for the pavement.’ We have always walked a beat on Water Street, and the guys at night still check doors on Water Street.”

The radiator badge will walk that beat once again. Gregoire, at Bushey’s request, has agreed to let Behr wear the badge on patrol before putting it on display.

“I got some goose bumps when Keith told us he was going to allow us to have it come back home,” Behr said.