Dylan McDermott

Connecticut police have ruled that Dylan McDermott's mother was murdered by her now-dead gangster boyfriend in 1967, according to local paper The Republican-American.

Waterbury police said they've found evidence that would be enough to file murder charges against John Sponza, whose body was discovered in a trunk shot to death in 1972, in the death of Diane McDermott. They also found evidence to implicate him in at least two other unsolved homicides.

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Diane's death was initially ruled an accident after Sponza, who lived with the McDermotts at the time, had told police that Diane accidentally shot herself after picking up a gun he had been cleaning. Police reopened the investigation last year after the actor contacted them. McDermott was 5 when his mother died.

After reviewing Diane's autopsy, H. Wayne Carver, the state's medical examiner, ruled that the gun found near her body was too small a caliber to have been the weapon used to kill her. Carver also found that the wound showed that the murder weapon had been pressed to the back of her head. Police Superintendent Michael Gugliotti told the paper that he was troubled by the lack of follow-up interviews and investigation after Sponza's claim 45 years ago.

"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 said. "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."

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McDermott met with Gugliotti and Mayor Neil M. O'Leary last year while in town for a fundraiser. "He said in order for me to survive and to get where I am today, I needed to bury that moment in my life deep within myself," Gugliotti said. "He said it wasn't until recently that I've come to the point in my life where I'm able to begin to process all of this and make it part of his life."

The Practice and American Horror Story star declined to comment to the paper, but his sister, Robin Herrera, said she is relieved by the findings. "I'm happy to know my mother wasn't mentally ill or depressed," she said. "Somebody took her from us; she didn't leave us."