Over two years after arresting a Harvard undergraduate and violating his civil rights, a Boston Police Department (BPD) sergeant was sentenced to nearly six years in prison yesterday.

A federal jury convicted Sgt. Harry A. Byrne Jr. in September of beating Garett D. Trombly ’03 after arresting the then-Cabot House resident near the Boston College campus shortly after midnight on Sept. 9, 2001. Byrne was also found guilty of four separate counts of attempted witness tampering in the aftermath of the beating.

Following yesterday’s hour-long hearing, U.S. District Court Judge Richard G. Stearns sentenced Byrne to 70 months in prison for each of the five counts, according to Mary Johnson, Stearns’ clerk. The terms will be served concurrently.

After serving his sentence, which will begin on Jan. 14, Byrne will spend two additional years in supervised release.

He will also be required to pay Trombly $7,717.40, an amount intended to cover medical and legal bills.

Byrne could have received up to 10 years and a maximum $250,000 fine for each of the five counts.

Trombly, who is now a student at Suffolk University Law School, wrote in an e-mail that he was relieved the affair was over.

“My primary concern was assurance that he could no longer be a police officer, so once the conviction came down, I had very little interest in the sentence,” he said. “The federal sentencing guidelines are relatively rigid and explicit, and taken with precedent, there wasn’t a great deal of speculation as to what the sentence would be on my part. I am glad to have been granted restitution of my legal fees, and hope this concludes my involvement in this affair.”

In September, Trombly told The Crimson that his decision to attend law school was influenced by his experience in Sept. 2001, when he was a junior concentrating in economics.

“This event crystallized my desire to pursue a career in justice,” he said. “I hope to some day help a victim of corruption like I was helped.”

During the two-week trial—which started in August after almost a year-long delay—prosecutors and witnesses graphically described how Byrne punched Trombly in the face with closed fists, held him by the throat with one hand while striking him with the other and threw him across the room into a bench. Trombly’s jaw was broken in the incident, forcing him to eat through a straw for two weeks.

Trombly had been arrested on charges including assault and battery on a police officer and resisting arrest after two escalating confrontations between Byrne and several of Trombly’s friends on Sept. 7 and Sept. 8, 2001. All charges against Trombly were dropped, but the BPD’s Anti-Corruption Division and the Federal Bureau of Investigation soon began investigations into Trombly’s allegations of abuse, resulting in Byrne’s suspension from active duty in Oct. 2001 and a federal indictment in Jan. 2002.

During the trial, Byrne admitted to striking Trombly, but he and his lawyer argued that Byrne had used reasonable force in a terrified, split-second reaction to seeing the student reach for what he thought was a weapon. Byrne said the object in question proved to be a cell phone, but Trombly and another BPD officer testified that the phone had been confiscated long before.

Byrne was also convicted on four counts of witness tampering for his concerted efforts to hush BPD officers who had witnessed the events.

—Staff writer J. Hale Russell can be reached at jrussell@fas.harvard.edu.

—Staff writer Simon W. Vozick-Levinson can be reached at vozick@fas.harvard.edu.