The detective leading the manhunt for a man suspected of killing two people in their own homes has urged him to give himself up.
James Allen is being urgently sought by police following the separate murders of Julie Davison, 50, in Whitby, North Yorkshire, and 81-year-old Colin Dunford in Middlesbrough.
The 35-year-old has previous convictions for violence and has served a custodial sentence, Detective Chief Superintendent Gordon Lang told a press conference in Middlesbrough.
Urging him to give himself up, he said: "James Allen, stop now. Do the right thing. Consider the consequences. You have inflicted terrible injuries and death on two families."
Police said there have been a number of reported sightings of Allen in Middlesbrough, Scarborough and Whitby since the two murders this week.
Mr Lang confirmed Allen was on court bail for an offence, although he did not disclose what it was. He also said Allen had had contact with the probation services and was being investigated for other alleged offences, which he would also not disclose.
Mr Lang warned residents to keep their homes secure and be careful when answering their doors.
He added: "Clearly this is a man who is a dangerous man, but we are putting absolutely everything into finding him, tracking him down and bringing him to justice. There's a massive police operation in place here. Over 100 detectives, two forces, not an inch between these two forces, absolutely working in partnership with one goal, and that is to find James Allen and arrest him. We are 100% committed to tracking him down. This is a 24/7 operation. If you see James Allen, do not confront him, dial 999."
Mr Lang said Allen, originally from Blackpool, knew 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. He said robbery was a possible motive behind the attacks, but stressed he was keeping an open mind.
A post-mortem examination on Mr Dunford, who was last seen alive at around 5pm last Sunday, showed he had suffered serious head injuries as a result of a significant assault. He was found dead at his terrace house in Leven Street, Middlesbrough, on Monday after he failed to appear at Samuelsons Working Man's Club, where he was a daily visitor. 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.