Neighbors who have known the homeowner for years are coming to his defense, saying they believe there's a lot more to the story.
Authorities said the shooting followed a dispute between the contractor and the homeowner, 75-year-old George Barr, inside the residence on the 400 block of Ripka Street.
Police will not say what the dispute was about.
The victim, identified as Salis Hanrahan of England, was part of a construction crew working on the home.
Hanrahan's wife, Roseann, shared photos of him and said he leaves behind a 1-year-old daughter.
Workers told police they were outside putting siding on the house when they heard a commotion inside. Hanrahan then walked out of the home and collapsed with a gunshot wound to the chest, police said.
"We don't know what happened in that house. Nobody does except them two," a neighbor said. "This whole thing is getting spun out of control."
Scott Thomas, who has lived on the block and known Barr for years, said when he heard the chaos happening outside, he initially went to ask Barr if he knew what was going on.
"I was going to ask George if he knew what it was. So for me to find out that it even had something to do with him is literally the last possible idea or thought of this house, of this happening," Thomas said.
Barr, described by Thomas as a retired firefighter, Vietnam veteran and an unofficial neighborhood patrol, was taken in for questioning immediately after the shooting.
Late Thursday night, police charged him with murder.
"This is not a person who showed any kind of anger or any kind of thing. For someone like that, who was a Vietnam vet, who was on Hamburger Hill, to grab a gun? I would only imagine there was some kind of threat there. That's my personal belief," Thomas said.
Hanrahan's wife described him as someone with a heart of gold, who always had a smile on his face, and who loved his family deeply.
Barr's family declined to comment. Police said homicide detectives continue to investigate what led up to the shooting.
Barr was arraigned Thursday night and was denied bail.
The investigation is ongoing.
Anyone with information should contact the Homicide Unit at 215-686-3334 or submit an anonymous tip by calling or texting 215-686-TIPS (8477).