The manhunt for a 35-year-old wanted in connection with "two brutal murders" continued on Friday.
More than 100 officers are involved in the search for James Allen following the deaths of Colin Dunford in Middlesbrough on Monday and Julie Davison in Whitby, North Yorkshire, on Wednesday.
Allen is known to police and members of the public are urged not to approach him but dial 999.
Detectives described the killings as "two brutal murders in the victims' own homes".
Cleveland Police and North Yorkshire Police issued a joint appeal to find Allen after officers linked the two deaths.
Davison, 50, who lived alone, was found dead by her sister at her rented flat in Church Square. She had suffered serious head injuries, police said.
North Yorkshire Police said they wanted a man with a dark-coloured mountain bike to come forward after he was seen near the flats at around 6.30am on Wednesday morning.
A post-mortem examination on Dunford, 81, showed he had also suffered serious head injuries as a result of a significant assault.
He was found dead at his terraced house in Leven Street, Middlesbrough, on Monday after he failed to appear at his favourite club.
Locals said the dead man was a daily visitor to the Samuelsons Working Mans Club directly opposite his home.
It is believed that when Dunford was not seen at the club where he often ate his evening meal, members became worried and the police were called.
Detectives said there was no sign of forced entry at the house.
Dunford was last seen alive at around 5pm on Sunday.
Temporary Detective Chief Superintendent Gordon Lang, head of crime operations for Cleveland Police, said: "Anyone who can carry out such callous acts needs to be caught as a matter of urgency.
"We have over 100 officers working on the incident to trace Allen and we are focusing our efforts in Cleveland and in the Whitby area of North Yorkshire.
"Anyone who sees him or who knows where he is, we would ask them to contact 999 immediately."
Allen is described as 5ft 7in, with a bald head and tattoos on both arms.