A Hingham man will serve at least a year and a half behind bars for beating a US Navy veteran outside a party in West Roxbury last year, Suffolk County District Attorney Daniel F. Conley said today.

Assistant District Attorney Melissa Brooks of Conley’s Major Felony Bureau recommended that THOMAS McCANN (D.O.B. 4/3/84) serve three to five years in state prison following his conviction Tuesday for assault and battery causing serious bodily injury.

Suffolk Superior Court Judge Diane Kottmyer instead sentenced McCann yesterday to two and a half years in a house of correction, ordering him to serve 18 months of that term up front with the balance suspended for a three-year probationary period. During that time, McCann must remain drug- and alcohol-free, undergo random urine screens for drug and alcohol use, take part in an anger management program, and seek or obtain full-time employment. If McCann does not abide by those terms, or if he reoffends during the probationary term, he could be ordered to serve out the remaining year behind bars.

McCann was indicted last year on a count of assault and battery with a dangerous weapon causing serious injury. During the four-day trial, Brooks introduced evidence and testimony proving that McCann attacked and beat the victim, then 33 and a West Roxbury resident, outside a party on Pleasantdale Road on June 6, 2010.

Brooks established that McCann showed up at about 12:30 a.m. with his sister and two friends. The victim was also at the party. At some point during the early morning, McCann’s sister and the victim began arguing inside the residence.

The argument escalated and moved outside, where McCann stepped in. Brooks introduced testimony that he used a tire iron to beat the victim, knocking the victim to the ground and causing a serious head injury. As a result of that injury, Brooks showed, the victim had to undergo brain surgery and lost about 40% of his peripheral vision.

McCann fled with his sister and associates in a black Mitsubishi. Boston Police established his identity through a series of interviews and obtained a warrant for his arrest. He was stopped in Hingham later on the afternoon of June 6 driving the Mitsubishi, and detectives recovered blood from the steering that proved to be a match with the victim’s DNA profile.

The tire iron was never recovered.

Michael Coffey was the DA’s assigned victim-witness advocate. McCann was represented by attorney Neil Madden.