Police say these four states should now be on alert for the 'Facebook Live' killer

Police in Cleveland are warning residents in the states of Pennsylvania, New York, Indiana, and Michigan to be on the lookout for a man who has been dubbed “The Facebook Live Killer.”

Steve Stephens, 37, was charged with aggravated murder early Monday after he allegedly murdered 74-year-old Robert Godwin on Easter Sunday afternoon while he streamed the violent incident live on Facebook, according to Cleveland police.

Facebook disputes that the video was streamed live, saying that Stephens did go live earlier Sunday, but the video he posted of the killing was posted to social media after the fact. The video was up for three hours before Facebook removed it, along with his account.

“This is a horrific crime and we do not allow this kind of content on Facebook,” the social media giant said. "We work hard to keep a safe environment on Facebook, and are in touch with law enforcement in emergencies when there are direct threats to physical safety."

In the disturbing video, Stephens can be seen walking up to Godwin, who was a passer-by in the area collecting aluminum cans in a plastic bag. Stephens told Godwin to repeat a woman’s name as he pointed a gun at Godwin., who did not appear to recognize the woman’s name.

“She’s the reason this is about to happen to you,” Stephens told him before pulling the trigger.

Stephens, who worked as a case manager for a behavioral health agency, claimed in a separate video posted to Facebook that he had killed over a dozen people.

"Like I said, I killed 13, so I'm working on 14 as we speak,” he said in the other video.

Police have not yet connected Stephens to any other killings.

"As far as we know right now, we don’t know where he’s at," Cleveland Police Chief Calvin Williams said at a news conference Monday morning. "The last location we had him at was the homicide.

"Early in this investigation we did have contact with him, direct contact with our detectives," he added. "They tried to convince him to turn himself in."

Williams also told reporters that Stephens' only previous criminal record was a long list of traffic violations.

The FBI is assisting in the investigation. The suspect is considered to be armed and dangerous.