Shot Pc David Rathband said today he was suing his own force because he was left "a sitting duck" when gunman Raoul Moat declared war on police.
The 43-year-old father of two was blinded in both eyes when the fugitive shot him during his rampage last summer.
Moat told a police 999 call operator he was armed and "hunting for officers" moments before the attack in July.
Pc Rathband was not warned of the threat and Moat was able to blast him as he sat unarmed in his patrol car on an A1 roundabout.
Pc Rathband then prevented other officers being harmed by radioing for help, despite bleeding heavily from wounds to his head and body.
He was in court when Moat's henchmen Karl Ness and Qhuram Awan were jailed for life earlier this month.
Hearing how the two helped keep the gunman one step ahead of the law was unbearable but had drawn a line under a chapter in his life, he said.
Pc Rathband is in training to run the London Marathon in April, to raise money for The Blue Lamp Foundation the charity he set up in the wake of his shooting.
The charity seeks to help emergency services staff who have been injured as they carry out their duty by a crime.
He told The Victoria Derbyshire programme on BBC Radio 5 Live he was suing Northumbria Police because what happened to him "could and should" have been avoided.
He said: "There are individuals within Northumbria Police that made terrible mistakes and should be held accountable.
"If you know that somebody has made a direct threat towards someone you either remove that threat or remove the person that is being threatened.
"That is just common sense and they did not do that.
"I did not know that someone had a gun and was intent on killing police officers. I was not warned.
"If I had known, I would not have been shot.
"I would not have been in the position that I was.
"I was a sitting duck.
"Something has gone drastically wrong there."
Pc Rathband said he still intended to return to work to finish his shift.
The traffic officer, who has been a Northumbria Police constable for 11 years, said he hoped the force would learn from his legal action.
He said: "They have to accept responsibility for their mistakes and be accountable.
"That way they can put things right."
He said witnessing the killer's accomplices jailed for more than 60 years at Newcastle Crown Court had laid to rest some ghosts.
He said: "Moat used to visit me in my dreams.
"On the night they were sentenced Raoul Moat visited me for a couple of seconds.
"Normally I would speak to him for a couple of seconds to get him to go away but this time he appeared and I just laughed in his face, and he went away.
"He can't get to me now.
"He had done what he tried to do and he failed.
"The sentences were the end of a chapter in my life but they did not bring closure, so to speak. I don't know what that means."
Pc Rathband is now training for a guide dog.
He will run the London Marathon strapped to a helper, and aims to complete the race in under six hours.
Questions over the amount of warning the force had before the shootings are already part of an Independent Police Complaints Commission investigation.
Pc Rathband was blasted in the face in Newcastle in July after Moat, 37, who later shot himself dead, had wounded ex-partner Samantha Stobbart, 22, and killed her lover Chris Brown, 29.
A Northumbria Police spokesman said: "We look forward to welcoming David back to the force as soon as he is able.
"We can confirm that we have received correspondence from his lawyers and are considering the contents."