Police recently reopened a 45-year-old case involving Dylan McDermott’s mother, finally concluding that she was murdered by her ex-boyfriend.

When McDermott was 5, his mother was shot to death in an incident that police initially ruled as an accident. The suspect in the crime is the mother’s ex-boyfriend John Sponza who had ties to organized crime syndicates. He told police that his girlfriend accidentally shot herself, after picking up a gun that he was cleaning.

Last year, Waterbury police finally reopened the case after Dylan himself called the station with unanswered questions.

The medical examiner reviewed the autopsy and saw the inconsistencies. The weapon found was not only too small to have caused her injuries, but her death was caused from a shot at the back of her head.

“What troubled me was that there was very little follow up other than the statement Sponza had given to police,” Police chief Michael Gugliotti explained.

“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,” he also added. “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 also led to evidence that links Sponza to two other homicides. Unfortunately, the suspect cannot be tried, as he was shot to death in 1972, when his body was found in the trunk of a car in a store parking lot.

Experiencing this traumatic event at a young age, McDermott found ways to cope with the loss.

“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 recalled his conversation with McDermott. “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.”

Watch the actor’s interview with Chelsea Lately below.