YORKSHIRE Ripper Peter Sutcliffe could apply for parole in just six years' time.

But it is understood moves are afoot to keep him jailed for life. And it would be a brave judge that would ever consider releasing the man responsible for 13 horrific murders and at least another eight attacks.

Senior police chiefs also suspect Sutcliffe of carrying out further crimes.

He was convicted of going equipped for theft in Bradford's red light area as far back as 1969 - and the weapon he had with him at that time was a hammer.

Yet the first proven attack happened six years later in July 1975.

Sutcliffe later admitted two other attacks to former West Yorkshire Chief Constable Keith Hellawell - attacking a 14-year-old girl in Silsden near Keighley in August 1975 and a 22-year-old student in Ilkley in March 1979.

Both survived.

After Sutcliffe was found guilty following his trial at the Old Bailey in May 1981 the judge, Mr Justice Boreham, sentenced him to life with a minimum of 30 years.

But he wanted Sutcliffe to serve longer and said: "I express my hope that when I have said life imprisonment it will mean precisely that.

"Yorkshire does not lack fortitude, but I am left in no doubt that women from a wide area were in deepest fear and I have no doubts too that the fear spilled over to their menfolk."

The Home Office has confirmed that under the Criminal Justice Act 2003, the minimum sentences must be set by judges and Sutcliffe's case is due to be heard at the High Court in London.

Without this new law, the issue of Sutcliffe's release would have been a decision for the Home Secretary.

That power has now been removed from politicians, but judges can impose whole life tariffs on Britain's worst criminals.

A Home Office spokeswoman said: "A formal tariff will be set for Sutcliffe under the new arrangements by a judge and the court will look at his case retrospectively."

The murder convictions meant Sutcliffe was sent to a normal jail - Parkhurst on the Isle Of Wight.

In 1984 after assessment by psychiatrists they concluded his mental state meant he had to be transferred to Broadmoor Mental Hospital.

Sutcliffe has been attacked several times. While in Parkhurst an inmate slashed his face with a broken coffee jar.

In 1997, he was attacked by another patient at Broadmoor who stabbed him in both eyes with a pen. Sutcliffe lost the sight in his left eye as a result of that attack.

* Huddersfield MP Barry Sheerman believes there should be a permanent memorial to the Ripper victims.

Mr Sheerman, who became the town's MP in 1979 at the height of the Ripper killings, said the memorial could be a work of art or even something like a fountain.

"It was just such a tragic end to so many lives - most of them young girls - and it would be good for the people of West Yorkshire to have something permanent to remember them by," he said.