Police were warned by prison staff that suspected gunman Raoul Moat may have been planning to harm his ex-girlfriend the day before he allegedly shot her and killed her new boyfriend.
As the hunt for the fugitive continued today, Northumbria Police temporary Chief Constable Sue Sim said the warning came from Durham Prison on Friday.
She added that the case had been referred to the police watchdog.
Moat, from the Fenham area of Newcastle, was released from prison on Thursday after being jailed for 18 weeks for assault.
On Saturday Moat, 37, allegedly shot Samantha Stobbart, killed her boyfriend Chris Brown and fled.
The next day the former nightclub bouncer allegedly shot and injured Pc David Rathband.
At a press conference police said Miss Stobbart, 22, was no longer in a critical condition and was "improving".
She issued a direct appeal to Moat, through the police, saying: "Please give yourself up. If you still love me and our baby you would not be doing this."
Detective Chief Superintendent Neil Adamson revealed police had received a hand-written letter in the last 24 hours purportedly from Moat and urged him: "I want you to realise you do have a future. We can only help you with this if you make contact with us directly."
The detective said there were indications that other people may be at risk and a number of them had been given police protection.
Miss Stobbart was being "appropriately protected", he added.
Tensions remained high in Newcastle today, where people were arrested and released by armed police in at least two incidents.
Moat mistakenly believed Miss Stobbart was having an affair with a police officer.
He is understood to have fired at Miss Stobbart - with whom he had a six-year on-off relationship - through the living room window of a house in the Scafell area of Gateshead.
Moments later Mr Brown, 29, is believed to have left the property - only to be struck down around 50 metres from the front door.
Less than 24 hours after the attack, a man identified as Moat was linked to a shooting in East Denton, Newcastle.
Pc Rathband, 42, a married father of two with 10 years' experience on the force, was shot in the face and chest through the passenger window of his car in an "unprovoked" attack while on duty. He had been parked on a roundabout.
Ms Sim said Pc Rathband underwent surgery last night and his condition remained critical but stable.
She explained the force had voluntarily referred the case to the Independent Police Complaints Commission (IPCC).
"Northumbria Police were not informed that Mr Moat intended to shoot or kill Samantha Stobbart," she said.
"We were informed on Friday afternoon by Durham Prison that Mr Moat may intend to cause serious harm to his partner.
"We acknowledge that it is important that these matters are investigated thoroughly, and I have voluntarily referred this aspect to the Independent Police Complaints Commission, and we will of course fully co-operate with the Independent Police Complaints Commission."
Ms Sim also said: "Our thoughts remain with the family and friends of those who have been killed and injured at this difficult time.
"We remain absolutely committed to finding Raoul Thomas Moat and are using every resource available to bring this to a conclusion as quickly as possible.
"This remains our primary objective, as does the safety of the public and my officers."
Mr Adamson said Moat's letter set out his concerns and a "general grievance" with the police.
But emphasising the fact Miss Stobbart was not in a relationship with an officer, he urged Moat to get in touch.
The message from Miss Stobbart stated: "When you came out of jail I told you I was seeing a police officer.
"I said this because I was frightened. I have not been seeing a police officer."
The detective also appealed for anyone helping to protect Moat to come forward.
"Our investigations so far lead me to believe that there are a number of people who may be aware of Mr Moat's whereabouts and movements," he said.
"They may even have had contact with him over the weekend.
"We need to speak to these people and I would appeal to them to come forward."
Moat is believed to be in the North East still, although he also has access to vehicles, he added.
An IPCC spokesman said the watchdog had received a referral from Northumbria Police in connection with intelligence they had received about Raoul Moat.
"The IPCC will undertake an assessment to determine what involvement, if any, it should have in any future investigation," he said.
Moat is described as 6ft 3in tall, white, of large muscular build, with very short or shaven blond hair and blue eyes.
Members of the public were warned not to approach him.
Anyone with information should call 03456 043043 or Crimestoppers on 0800 555111.Reuse content