The sole suspect in the gruesome killing of a 74-year-old man that was broadcast live on Facebook has shot himself after a brief chase, Pennsylvania police have said.

Steve Stephens, 37, was spotted in Erie County by state police who tried to pull him over. After what was reportedly a brief pursuit, Stephens turned a gun on himself.

Stephens was suspected of killing Robert Godwin Sr, 74, on Sunday 16 April as he was walking home from a family Easter meal in Cleveland, Ohio. Godwin was a father of 10 and grandfather of 14.

In a number of emotional interviews since the killing, Godwin's family said that they forgave Stephens for the alleged murder but urged him to turn himself him.

"Although I forgive him, there is still a penalty that he must pay for what he did to my dad and so I would want him to turn himself in," Godwin's daughter, Debbie, told CNN.

Police in Cleveland had called for help finding Stephens earlier on Tuesday, saying that they'd received 400 tips on his whereabouts but had not been able to narrow their search.

On a video that was shared on Facebook before the social media company took it down, a man alleged to be Stephens can be heard saying "Here's somebody I'm about to kill. I'm about to kill this guy right here. An old dude." Godwin can then be seen falling to the ground as a gunshot is heard.

In a blog post, Facebook's VP of Global Operations Justin Osofsky said: "As a result of this terrible series of events, we are reviewing our reporting flows to be sure people can report videos and other material that violates our standards as easily and quickly as possible."