Steve Stephens, 37, had been the subject of a nationwide manhunt in the wake of Sunday's killing in Cleveland.
The incident was the latest grisly crime posted on Facebook, reviving questions about videos posted on the world's largest social network, and how -- or if -- they can be monitored. The footage was eventually taken down.
Stephens "was spotted this morning by PSP members in Erie County. After a brief pursuit, Stephens shot and killed himself," Pennsylvania State Police said on Twitter.
Stephens was accused of fatally shooting Robert Godwin Sr in Cleveland, Ohio as the 74-year-old grandfather was walking home from dinner on Easter Sunday.
More From This Section
Stephens is believed to have videotaped his actions and published it on Facebook, along with another video threatening to kill others and claiming he had already killed 13 people.
Authorities said Godwin is the only known victim despite an extensive investigation into Stephens's claims to have killed others.
Stephens's mother told CNN she called him on Sunday after learning about the video, and he had told her he was shooting people because he was "mad with his girlfriend."
Stephens's photo had gone up on billboards and more than 400 tips had poured in before the suspect was spotted in Pennsylvania.
"When people go on the run like this, at some point in time, they need help," Cleveland police chief Calvin Williams told a news conference earlier today, before Stephens was found dead.
The car Stephens was thought to be driving, a white Ford Fusion, did not contain GPS tracking devices, authorities said.
Members of Cleveland's clergy had asked Mayor Frank Jackson to convey their desire to help Stephens, should he want to seek out their counsel.
"I don't want that man to die, I want him brought to justice," one of his sons, Robby Miller, said.
"One thing I do want to say, is that I forgive (the killer).