Bucks County investigators confirmed the death Daniel Mooney. He was once a person of interest but now is called the prime suspect in the brutal murders of a young married couple.

MORE: Couple found dead inside Northampton Township home

"Our team is unequivocally convinced that he killed the victims and he acted alone," First Assistant District Attorney Gregg D. Shore said.

Detectives say 26-year-old Mooney once lived near Tyler and Christina Roy and for some reason he went back to the Churchville neighborhood on North Kitty Knight Drive entered the Roy's home through an unlocked door and confronted the couple.

"Both victims were stabbed multiple times and both victims were shot," Shore said. "It's clear that there was a struggle in the upstairs of the home," Shore said.

Authorities say the killer used a rifle that belonged to Tyler Roy. They also tell FOX 29 Mooney stole their car, dumped it and turned up in Kensington to panhandle before being pronounced dead at a hospital.


"We were advised by the Philadelphia Police Department that a John Doe had entered into the hospital in the early morning hours and had died as a result of drug overdose," Shore said.

The biggest question is still why?

"It's very difficult to say what this was all about. It's obvious that the suspect has struggled with drug addiction issues over the last time," Shore said.

A painter working on the Roy's home discovered their bodies Tuesday morning--sending a neighborhood into fear with the killer still at large. While tensions have eased with Mooney's death work continues on a case that's even tough for seasoned violent crime investigators.

"You look at these lives that are lost and you see a lot of hope when you look at both of their faces. Both of their faces are faces that are young vibrant people that have a whole life ahead of them," Shore said.