Anthony Galla, 31, was tracked to the Summit Motor Inn in Upper Darby at about 6 p.m., WCAU-TV reported. Hours earlier, at 1 a.m., he allegedly fired shots at a former girlfriend's home in Mount Carmel in central Pennsylvania, hitting her new boyfriend in the foot.
Upper Darby Police Chief Michael Chitwood said marshals went to the motel with a warrant, the Philadelphia Daily News reported. When they arrived, a man standing outside ran into Galla's room yelling the police were there, Chitwood said.
Chitwood said Galla opened fire, prompting marshals to shoot back, killing him.
The man who was outside, identified as Galla's brother, and Galla's current girlfriend were arrested.
Investigators say Galla had served in the military and as a part-time officer for several police departments in central Pennsylvania.