A PSYCHOPATHIC killer who beat a defenceless doctor to death could be released from prison within months after overturning his "whole life" sentence.

Evil loner Reg Wilson was jailed in 1991 for the motiveless killing of North-East consultant doctor David Birkett. He was sent to prison with a judge's recommendation that he never be released.

But the 42-year-old, from Middlesbrough, could be freed within weeks after the High Court ruled there was no justification for his "whole life" tariff, despite the extreme violence of his crimes.

Wilson, 42, had one aim in life - to commit the perfect murder.

He battered Dr Birkett to death at the consultant's six-bedroomed house in Linthorpe, Middlesbrough, after posing as a motorcycle despatch rider in February 1990.

Police who eventually caught the killer, thanks to a fingerprint left at the murder scene, believed he planned a series of murders.

After the killing, he sent letters to detectives taunting them and boasting he would never be caught.

And when they searched his home in Riverdale Court, Whinney Banks, Middlesbrough, detectives found plans to lure unsuspecting police officers to their deaths. Wilson wrote: "Plan to kill as many pigs as I can before they kill me. Kill one, frighten a hundred."

And he scrawled: "You ain't seen nothing yet" on the walls of an abandoned house he used as a hideout in the town's Union Street.

As he was led from the courtroom in 1991, Wilson shouted: "You might contain me, but you'll never control me. Understand that."

Wilson was once labelled one of Britain's most dangerous prisoners and was moved to a secure unit alongside the notorious hostage-taker Charles Bronson and serial killer Robert Maudsley.

In 1996, he tried to escape from high-security Frankland Prison, near Durham City, and had started to saw through the bars of his cell. His attempt was only foiled when a homemade ladder proved too heavy to carry.

Now, following the High Court's decision yesterday, Wilson has been given permission to plea for his release before a parole board.

After reviewing his case, Mr Justice Tugendhat ruled there was no justification for a "whole life" tariff - and cut his minimum term to 18 years.

The decision has stunned campaigners fighting to keep convicted killers off the streets.

Barbara Dunne, whose 31-year-old son, Robert, was killed with a Samurai sword yards from his Middlesbrough home, in January 2003, organised the Walk for Justice protest march in town.

She said: "I think it is a disgusting decision - what about the life sentence the family is suffering? "The authorities are not taking the families of victims into consideration. It is like they are knifing the families in the back with these decisions. This man hit his victim over the head 17 times - how can he deserve to be free? "It is horrendous that this man could be released from prison. I know he has to go before the Parole Board, but Mr Wilson's family will not get the opportunity to speak. They are taking away people's right to justice."

A National Victims' Association spokesman said: "The victims and families of homicide that this charity represent are disgusted and appalled by this decision.

"It is a deep insult to the memories of these people that prisoners' sentences are cut short."

At London's High Court yesterday, the judge emphasised that Wilson would only be freed if he could convince the Parole Board it was safe to do so. He ruled that, despite the degree of planning and brutality of the killing, it was not a case where a whole-life tariff was justified. He said the "starting point" for setting Wilson's minimum jail term should be 15 years, before he increased that to 18 years to take account of the extreme violence used in the murder.

He said it was not disputed that Wilson was suffering from an untreatable psychopathic disorder when he killed Dr Birkett. After his conviction, the trial judge, Mr Justice Potts, had assessed Wilson as highly dangerous and commented on his "considerable potential for causing harm to others".

Recommending that he serve the whole of his life behind bars, Mr Justice Potts also referred to another indictment against Wilson, which was left on file, accusing him of attempting to murder a prison officer while he was awaiting trial.

A police spokeswoman said: "We accept the ruling of the Royal Courts of Justice that the minimum tariff has been set for 18 years.

"However, this means that Wilson would still have to satisfy the Parole Board that he was safe enough to be released back into society, and we will monitor this very closely. Our thoughts, as always, remain with Dr Birkett's family, who we have been in close liaison with over the past few days."

The Ministry of Justice declined to comment.