PENN HILLS, Pa.—Police say a homeowner has slain one of three men who forced their way into his family's home in suburban Pittsburgh, but authorities haven't revealed how the intruder was killed or why they believe he was three in the first place.

Allegheny County detectives and Penn Hills police have yet to release the victim's name or the name of the man who owns the home in this suburb just east of the city.

Police say neighbors leaving for work called 911 to report seeing a body on the front steps of the home about 7:30 a.m. Wednesday.

When investigators arrived, they learned the man who lives there—reportedly with a woman and two school-age children—wounded one of the intruders, possibly by stabbing him.

The homeowner then pushed the intruder outside where he was found dead.