CHICAGO, United States (AFP) — US police widened a manhunt yesterday for a gunman who shot and killed an elderly man on Facebook Live in a seemingly random Easter Sunday attack, and then vowed to continue killing.

Police in Cleveland, Ohio said they believe the suspect, 37-year-old Steve Stephens, is armed and dangerous, and have alerted authorities in four neighbouring states to be on the lookout for him.

Robert Godwin Sr, 74, was shot and killed on Sunday, apparently picked out at random as he walked home after an Easter dinner, police and local media reported.

“We know that Steve is still out there someplace,” said Cleveland police chief Calvin Williams. “We don’t know his condition and, of course, right now we don’t know his location.

We’re asking the public to remain vigilant.” In a video uploaded to Stephens’s Facebook page, a man resembling him is seen exiting a vehicle and approaching his victim, who is shown with a gun to his head and then falling to the ground after a shot is fired.

“I killed 13, so I’m working on 14 as we speak,” the suspect says in a second video clip. “I’m just driving around hitting mother f…, man.

I just snapped man.” The videos were subsequently taken down by Facebook. Police said Stephens broadcast the killing on Facebook Live but said they have not verified his claim to have committed other murders.

Stephens’ mother told CNN she called him on Sunday after learning about the video and he told her he was shooting people because he was “mad with his girlfriend”.

Police said the woman he alluded to was in a safe place. Cleveland detectives also made contact with Stephens by phone early in the investigation, Williams said.