WORCESTER — A former city firefighter was sentenced to jail Monday after pleading guilty to charges of unlawfully possessing several firearms, including a sawed-off shotgun.

Jonathan Peters, 30, formerly of 66 Indiana St., was sentenced to 18 months in the House of Correction, with 3 years of probation to follow, after pleading guilty in Worcester Superior Court to possession of a sawed-off shotgun, three counts of possessing a firearm without a firearm identification card, failure to secure a large-capacity weapon and unlawfully possessing ammunition.

The sentence imposed by Judge Janet Kenton-Walker was recommended by Assistant District Attorney Edward N. Karcasinas Jr. and Mr. Peters' lawyer, Anthony M. Salerno.

A total of 33 additional charges, including multiple firearm offenses, threatening to commit a crime, stalking in violation of a restraining order and intimidation of a witness were dismissed as part of the plea agreement in the case. Mr. Peters, a U.S. Army veteran who served two tours of duty in Iraq and said he has been diagnosed with severe post-traumatic stress disorder, had been accused of stalking and threatening his estranged wife, Jean Peters, in January 2013.

The couple have since divorced.

Police seized a number of firearms in a search of Mr. Peters' home after his estranged wife accused him of threatening to kill her. Authorities said some of the guns that were confiscated were loaded.

Mr. Peters became a probationary firefighter in June 2012 and was placed on unpaid leave after his arrest in early 2013. He has since lost his job with the Fire Department, according to Mr. Salerno.

Mr. Salerno told Judge Kenton-Walker that the firearms his client was charged with possessing unlawfully were legally purchased in Georgia, but that Mr. Peters did not have a firearm identification card or a license to carry a firearm in Massachusetts.

Mr. Salerno said the weapons were never used in the commission of any crime and were now being transferred to Mr. Peters' ex-wife, also a gun enthusiast, as part of the marital estate.

Ms. Peters told Judge Kenton-Walker that she agreed with the proposed disposition of Mr. Peters' case. Calling her former husband a "decorated soldier," she said she believed his PTSD affected his thinking in his dealings with her.

As conditions of probation, Mr. Peters was ordered to undergo mental health and substance abuse evaluations and any related treatment deemed appropriate by the court. He was also ordered to continue with counseling he has been receiving through the Veterans Administration.

Ms. Peters told the court that she believed her ex-husband could "become the man he was" if he receives the help he needs.

The possession of a sawed-off shotgun charge to which Mr. Peters pleaded guilty carries a minimum mandatory sentence of 18 months in the House of Correction. He was given credit for 148 days spent in custody awaiting trial.

Judge Kenton-Walker told Mr. Peters she would consider letting him off probation in two years if he complies with all the terms and has no further difficulty with the law.

She said she hoped the Veterans Administration would provide him with the counseling he needs.

"I want our country to be proud of you, and I want you to be proud of yourself again," the judge said.

Contact Gary V. Murray at gary.murray@telegram.com. Follow him on Twitter @GaryMurrayTG