WOBURN — As the prosecutor told the jury how Kristen Pulisciano was viciously stabbed more than 30 times in her Burlington home, her friends and family shuddered, and gently sobbed.
Just hours later, as the jury delivered a guilty verdict against Pulisciano’s killer, longtime boyfriend Christopher Piantedosi, they gasped in relief. In the hushed courtroom, they held each other in tearful embraces.
Piantedosi, 40, was found guilty Monday of first-degree murder. The jury rejected his defense of mental incompetence and returned its verdict after just three hours of deliberations. Middlesex Superior Court Judge Diane Kottmyer sentenced him to life in prison without possibility of parole.
Pulisciano’s death in May 2012 drew widespread attention because it was witnessed by a teenager who was having a video chat with Pulisciano’s 15-year-old daughter, who tried to stop the attack.
Prosecutors said the fatal attack came after Pulisciano, 38, ended the longtime relationship and was the culmination of years of abuse.
“This was his final attempt to control her,” said Nicole Allain, a Middlesex assistant district attorney who prosecuted the case. “There is a history of abusive behavior here.”
In her closing arguments delivered Monday, on the 11th day of the trial, Allain said Piantedosi grabbed a kitchen knife and attacked Pulisciano after she ordered him to leave the house.
“She was moving on, but the defendant was not,” Allain said. “He wasn’t going to accept it.”
During the attack, Allain said, Pulisciano cried out: “Chris, stop. I love you.” Piantedosi replied, “You’re going to die,” as he continued his assault.
Just minutes after the attack, he sent a text message to a friend that read “She is dead. See you later.” In a later message, he wrote “It’s done. She’s gone. I stabbed the [expletive] out of her.”
Allain said the message showed that Piantedosi was fully aware of his actions, contrary to his legal team’s argument that he was not in his right mind.
Piantedosi later discarded his bloody clothes and cellphone in a strip mall dumpster, changing into clothes he already had in his car.
“Right down to another pair of socks,” Allain said.
Piantedosi later turned himself in to police, driving into the parking lot of the State Police Weston barracks, and confessed to the slaying, prosecutors said.
Piantedosi’s lawyer, Michael Collora, acknowledged that Piantedosi killed Pulisciano, saying he did not want to insult the jury’s intelligence by arguing otherwise.
But he asserted that Piantedosi was under the influence of prescription drugs that exacerbated his mental illness, sending him into an uncontrollable rage.
“He was not responsible for his criminal actions,” Collora said in his closing arguments.
Piantedosi has bipolar disorder and had battled depression in the days and weeks before the attack. He had lost his job and was living with his parents, diminishing his “feelings of self-worth,” Collora said.
The medication he was taking for his depression could have brought on a manic episode, Collora said. “This is absolute evidence of mania caused by drugs.”
But Allain said Piantedosi had demonstrated “hostility and aggression toward Kristen for years.”
“This was a brutal, and painful, and slow death,” she said. “Hold him accountable for ending Kristen’s life.”
Piantedosi showed no emotion as the jury read its verdict. Earlier in the day, as Allain described the fatal attack, he yawned, infuriating Pulisciano’s family.
In a statement issued after the verdict, Pulisciano’s family urged the public to “learn from Kristen’s tragic story.”
“This is a tragedy that no family should have to endure,” the statement read. “Kristen lived in a world of domestic violence which she hid from everyone. We beg anyone who is in an unhealthy relationship to reach out and get help. . . . If you have a friend in a bad relationship, don’t stop trying to help.”Peter Schworm can be reached at email@example.com. Follow him on Twitter @globepete.