A push from "American Horror Story" star Dylan McDermott has led police in Waterbury, Conn., to re-investigate the 1967 death of his mother and conclude that her gangster boyfriend at the time shot and killed her, according to the local newspaper the Republican-American.

The boyfriend, John Sponza, who was found shot to death in the trunk of a car five years later, told police at the time that McDermott's mother accidentally shot herself after picking up a gun he had been cleaning.

But the Connecticut medical examiner who recently reviewed the autopsy says the gun used in the murder — which couldn't have been the one found by McDermott's mother's body — had been pressed to the back to her head. As a result of the reopened investigation, police have also been able to tie Sponza to two other unsolved murders.

Authorities now fault police at the time for the lack of follow-up. The actor, who was 5 when his mother died, told police recently that he remembers Sponza getting into violent fights with his mother, but Sponza told police at the time that he rarely fought with McDermott’s mother.

McDermott reached out to police superintendent Michael Gugliotti after meeting him at a fundraiser last year. "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 tells the newspaper. "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."

McDermott didn't comment about the new findings, but his sister, Robin Herrera, says she was relieved to rule out the possibility her mother had committed suicide. "Somebody took her from us; she didn't leave us."

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