Josiah Alexander

NEW HAVEN -- Daniel Petrillo Thursday pleaded guilty to first-degree manslaughter in exchange for a deal that will keep him in prison for 10 years in the stabbing death of Josiah Alexander during a fight at a party in Westville two years ago.

Petrillo, who is now 23, had been charged with murder in the crime, which occurred Nov. 21, 2010 at 15 Westerleigh Road.

Alexander, of 287 Ashmun St., was 23 at the time of his death.

Senior Assistant State’s Attorney Brian Sibley Sr. told Superior Court Judge Roland Fasano that Alexander’s family had had “a change of heart” and were “being compassionate” in their input about the sentence.

“They decided they would leave it up to the court, as long as he pleaded guilty and accepted responsibility for Mr. Alexander’s death,” Sibley said. “Since they can’t bring him back, they want to get on with their lives.”

Under the agreement, Petrillo June 1 will receive a 20-year sentence, to be suspended after he serves 10 years. He will then face five years of probation.

Alexander’s friends told police Petrillo became enraged when Alexander took a sip from Petrillo’s bottle of liquor.