Concord — A 27-year-old North Haverhill man was sentenced on Wednesday to 18 months in federal prison after he pleaded guilty in May to two counts of being a felon in possession of a firearm.

Thomas S. Harris sold two firearms to a pawn shop in Lisbon, N.H., in August and September 2016, according to a news release from the U.S. Department of Justice.

Harris is a convicted felon, which makes it illegal for him to posses firearms.

“In order to protect public safety, we must keep firearms out of the hands of criminals,” U.S. Attorney Scott Murray said in the release. “Through Project Safe Neighborhoods, we aggressively enforce federal gun laws and work to improve the safety and security of our communities.”