Dylan McDermott's Mother Murdered, 'Practice' Actor Gets Resolve

A re-opened police investigation has concluded that actor Dylan McDermott's mother was killed by her boyfriend, who may also have been responsible for two other homicides.

Dylan McDermott, an actor from "The Practice," lost his mother in 1967 when he was only five years old. Now at the age of 50, the actor has discovered that his mother was murdered, according to the Associated Press.

The investigation was re-opened last year after the actor called Westbury Police to make an inquiry into the case of his deceased mother, Diane McDermott.

Diane's death was originally ruled an accident after her boyfriend at the time, John Sponza, claimed that she had shot herself by mistake. Sponza stated that McDermott shot herself while handling a gun that he had left out because he was cleaning it.

Sponza had been linked to organized crime in the past and was a "drug-abusing gangster" according to the American Press. He was killed in 1972, found shot to death in the back of a car that was left in a Massachusetts grocery store parking lot.

Police Superintendent Michael Gugliotti, who worked on the case, admitted that the previous investigation had failed to tie up some loose ends.

"Sponza is telling the police that night that he very rarely, if ever, had arguments, yet everyone we spoke to, including Dylan, who was only 5 at the time, remembered very violent, vicious arguments," Gugliotti told AP News, discussing case details. "Dylan vividly recalls the amount of times, not only flashing the gun, but pointing it at the kid, saying, 'Shut up and get out of here.' He's still probably traumatized by that."

The reopened investigation has not only led to the possible conclusion of two other homicides for which Sponza may have been responsible for, but has also offered peace to the actor and his family.

"I'm happy to know my mother wasn't mentally ill or depressed," the actor's sister, Robin Herrera, said. "Somebody took her from us; she didn't leave us."