The shooting happened around 6:15 a.m. on the 900 block of Sylvania Avenue in Ridley Township.
Police say 72-year-old Jim DellaVecchia was waiting for his neighbor, 42-year-old Scott Robins, and fired as Robins left for work with a friend, Rick Wallace.
"I heard the first shot and saw the flash. I looked over at him and froze. I didn't know what to do," Wallace said in an exclusive interview with Action News.
Wallace was in a van when DellaVecchia allegedly shot Robins multiple times.
"He said 'Rick, run,'" Wallace recalled. "I jumped out of the truck and laid under the truck and I was going to hide there."
But Wallace says DellaVecchia then circled the truck.
"I could see him walking when he turned at the bumper, like he was coming around to my side. When I saw that I just rolled until I felt the dew on his front yard. When I felt that, I just took off running."
Wallace says DellaVecchia fired several times at him, but he was able to hop some fences and hide at Edgewood Elementary School.
Robins' stepdaughter, 23-year-old Kristen Snow, was unable to escape the gunfire. She ran outside when the shooting started and found her dad bleeding on the lawn..
That's when DellaVecchia allegedly shot her in the stomach. Snow is in stable condition but will go back into surgery on Tuesday.
Police picked up DellaVecchia from his house a few homes away on 9th Avenue.
Authorities removed evidence, including a .40 caliber gun and ammunition, from DellaVecchia's home. Police say he was just getting out of the shower as police arrived.
DellaVecchia was taken into custody but has since been hospitalized in stable condition. Police say, while he was in his cell, DellaVecchia intentionally rammed his head against the wall.
He is facing murder charges.
DellaVecchia's property butts up against Robin's, and neighbors say DellaVecchia had been angry for weeks over a shed Robins built, though the animosity has been known throughout the summer.
"Not that I ever thought it would come to this. I mean it's a shed. He wasn't bothering anybody," said neighbor John Hoffman.
"It seems like it's been an ongoing domestic, all summer long. We've been here five or six times, domestics back and forth, neighbor complaints back and forth," said Lt. Scott Willoughby of the Ridley Township Police.
Meanwhile, Wallace says Robins' last act was a life-saver.
"I'm thankful that I got away," Wallace said. "He thought to tell me to run, you know? Saved my life."