A huge manhunt is under way in Ohio for a suspect who police said shot and killed an elderly passer-by and posted the murder on Facebook.
Police urged the man to turn himself in, but he remained on the loose into the night.
Law enforcement officials identified the suspect as Steve Stephens, and Cleveland Police Chief Calvin Williams said officers were searching for him in the Cleveland area and beyond.
The victim was identified as 74-year-old Robert Godwin Sr.
Facebook said the suspect did go live on the social media site at one point during the day, but not during the killing.
Police had earlier said on Sunday that Stephens had broadcast it on Facebook Live.
In the video, Stephens gets out of his car and appears to randomly target Mr Godwin, who was holding a shopping bag.
Stephens says the name of a woman, whom Mr Godwin does not seem to recognise.
"She's the reason that this is about to happen to you," Stephens told Mr Godwin before pointing a gun at him.
Godwin can be seen shielding his face with the shopping bag.
Cleveland Mayor Frank Jackson publicly urged Stephens to turn himself in to police and not to "do any more harm to anybody".
"Any problems he is having, we can have a conversation," Mr Jackson said.
In a separate video, Stephens claimed to have killed more than a dozen other people.
Mr Williams said police have not verified any other shootings or deaths.
"There are no more victims that we know are tied to him," he said.
The chief also said they have been talking to the family and friends of Stephens, who is employed at Beech Brook, a behavioural health agency with headquarters in Pepper Pike, near Cleveland.
"We are shocked and horrified and we don't know anything more about it," agency spokeswoman Nancy Kortemeyer told WOIO-TV.
"We hope and pray that he is arrested as soon as possible and we hope and pray for a resolution quickly."
It was not immediately known what Stephens does for the agency, which said it will serve more than 18,000 children and families this year, according to its website.
The video of the killing was up on Facebook for about three hours before it was removed. Stephens' Facebook page has also been removed.
"This is a horrific crime and we do not allow this kind of content on Facebook," said a spokesman for Facebook.
"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."
Police said Stephens should be considered armed and dangerous. Late on Sunday, police issued an aggravated murder warrant for him and said that he may have travelled out of the state.
The FBI is assisting in the investigation.
- AP