By Joe Holden

ASTON, Pa. (CBS) — Aston Township police are working to solve a five-year-old murder case. Thirty-one-year-old John D’Amico was found shot and killed inside his own home, and the gunman is still at large.

It was Labor Day 2016 and the sound of fireworks echoed through this Aston Township neighborhood. It was after 9 p.m., but something was off.

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Neighbors called 911, explaining they thought they heard what sounded like gunshots.

“Someone had the wherewithal to realize that these fireworks weren’t right and they sounded a little different and they took the time and they called the police,” Aston Township Detective Joe Nardone said.

Nardone believes the timing of the gunshots with the fireworks was intentional.

“I believe this was done intentionally. The timing was precisely picked,” Nardone said.

D’Amico was found with a single gunshot wound to the head.

Nardone has been the lead investigator on the homicide case since Day 1.

“Mr. D’Amico was found inside his house, but his body was such where his head was out of the front door, but yet this body was still in the foyer,” Nardone said, “so it leads investigators, myself, to believe that John was trying, attempting to flee the house when he was shot.”

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Aston Township police have strong leads in their investigation, with information and statements implicating a man they’ve described as a suspect. He, though, is currently incarcerated in another case.

“We do have a suspect. It’s more than a person of interest. That person has been encountered by law enforcement in the past, many times. But currently, right now, there’s just not enough information,” Nardone said.

Investigators say even jailhouse interviews have helped the case along.

“I have actually had a cellmate come and approach the police and we have spoken to them and take statements from them, however, it’s still not enough to get us over that threshold,” Nardone said.

Police wouldn’t reveal theories on a possible motive.

Detectives say D’Amico left behind a large extended family, many of whom hope for justice in the five-year-old case.

Nardone says he thinks about D’Amico often and wants to bring his family some closure after all this time.

“John comes to me. John talks to me, and I don’t forget about John,” Nardone said. “I think there are people out there who have some information and can really, really further this investigation.”

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If you have information, please call the detectives of the Aston Township Police Department at 610-497-2633.