BANGOR – A former officer in the Calais Rod and Gun Club was sentenced Wednesday in U.S. District Court to three years and one month in prison for possessing firearms after he was dishonorably discharged from the Marine Corps.

Peter David Frost, 36, of Meddybemps was found guilty by a jury in April. He was arrested 14 months ago with 15 guns in his truck at the Calais Rod and Gun Club where an undercover Maine State Police detective had arranged to meet him and purchase a weapon.

U.S. District Judge John Woodcock sentenced Frost to 37 months in prison and two years of supervised release, the lowest possible sentence allowed under the federal sentencing guidelines. The judge did not impose a fine and allowed Frost to remain free on bail for another month. He is to begin serving his sentence Sept. 10.

“If the guidelines allowed me to impose a lower sentence, I would do so,” Woodcock said. “I think it is abundantly clear that you did not know that you were not allowed to possess firearms. … I am convinced if a law enforcement officer had told you that you couldn’t have possessed firearms, you wouldn’t have.”

Frost faced a maximum sentence of 10 years in prison and a fine of up to $250,000.

The same conviction that earned him a dishonorable discharge increased his federal sentence, Woodcock said Wednesday.

Frost enlisted in the Marines in 1987. He was found guilty of assault in 1992 after a military court-martial. He served five years in a military prison for shooting a security guard in the chest with a stolen gun during an attempted larceny.

In addition to serving as second vice president of the Calais Rod and Gun Club in Charlotte, Frost was certified by the National Rifle Association and taught safety courses at the club.

He resigned from the club shortly after his arrest.