A third police force has joined the manhunt for a violent convicted criminal suspected of killing two people in their own homes following a fresh sighting.
Police said James Allen, 35, was last seen in Leeds on Friday afternoon.
An urgent appeal to find Allen was issued by Cleveland Police and North Yorkshire Police following the murders of Julie Davison, 50, in Whitby, North Yorkshire, and 81-year-old Colin Dunford in Middlesbrough.
And West Yorkshire Police joined the search after Allen was seen on CCTV footage walking along Harehills Lane at 2.41pm on Friday.
But police said it was possible Allen was now in a different location and urged anyone who saw him to call 999.
Allen is considered dangerous and members of the public have been not to approach him but to contact police immediately.
Police also released CCTV images of Allen in Scarborough earlier this week.
The pictures showed Allen in a cash exchange in the seaside town on Tuesday and Wednesday and in a sports shop on Wednesday.
Temporary Detective Chief Superintendent Gordon Lang said the images showed Allen could be trying to change his appearance by growing his hair.
Mr Lang confirmed Allen stayed in a bed and breakfast, thought to be the Allerton Croft Hotel in Scarborough, on Wednesday night.
The detective said Cleveland Police had received hundreds of calls in response to appeals and urged anyone with information or anyone sheltering Allen to contact them.
"This is not a time for loyalty. There can be no loyalty at a time like this. This is the time to help the police," he said.
"Now is the time to be public-spirited."
Mr Lang issued a further direct appeal to Allen to hand himself in: "Give yourself up. Give yourself up now. You need to be in police custody, you know you need to be in police custody, you know what you've done.
"I think purely and simply by the tragic events that have unfolded, this is a man who cannot be at large, who needs to be arrested and that needs to happen as quickly as possible."
Allen has previous convictions for violence and was previously jailed for eight years for burglary and wounding with intent.
The detective also said Allen was on court bail for an offence of violence.
He said there had been contact between Allen and the probation services and he was being investigated for other alleged offences, although he would not disclose further details.
Mr Lang warned residents to keep their homes secure and be careful when answering their doors.
Mr Dunford, who was last seen alive at around 5pm last Sunday, was found dead with serious head injuries at his terraced house in Leven Street, Middlesbrough, on Monday after he failed to appear at Samuelsons Working Man's Club, where he was a daily visitor.
Detectives said there was no sign of forced entry at the house.
Ms Davison, who lived alone, was found dead by her sister at her rented flat in Church Square on Wednesday. She had also suffered serious head injuries, police said.
Police described the killings as "two brutal murders in the victims' own homes".
Allen, who is originally from Blackpool, is believed to have known Mr Dunford when he lived next door to him in Leven Street about a year ago but it is not thought Allen knew Ms Davison.
A black mountain bike was seen outside both properties and Mr Lang said it was feasible that Allen had cycled between
Middlesbrough and Whitby - a distance of more than 30 miles (48km).
However, he said no further information had been received about the bike and police were unsure what Allen's present mode of transport was.