The "hopeless alcoholic" who became known as Wearside Jack after he hoaxed police investigating murders by the Yorkshire Ripper was jailed for eight years yesterday.
On Monday John Humble, 50, from Sunderland, admitted four counts of perverting the course of justice when he appeared at Leeds crown court.
He was jailed for six years for each of the three letters he sent to police and the Daily Mirror and eight for the notorious tape, which shifted the police investigation away from Yorkshire to Wearside. All sentences will run concurrently.
The recorder of Leeds, Judge Norman Jones QC, said it could not be said that Humble's actions caused or directly led to the deaths of three women who were murdered after the hoax letters and tapes were sent. Nor could it be said that Peter Sutcliffe would have been caught earlier.
"The least that could be said was these victims would have stood a better chance of not being attacked had these police resources been directed in West Yorkshire," said the judge.
He told Humble: "Perverting the course of justice is a serious offence because the intention of the offender is to manipulate our justice system and produce injustice.
"In this case the manner of your offending, if not unique, is almost so. You planned to manipulate the process of the investigation of one of the most horrific series of murders ever seen in this country. You warped and bent its path away from the true killer.
"You did that with an indifference to the potentially fatal consequences which was breathtaking.
"I'm satisfied that one of the factors that may well have contributed to him [Sutcliffe] remaining at large for so long was your behaviour."
In mitigation, Simon Bourne-Arton QC said Humble was a hopeless alcoholic who had lived with the secret of what he had done for 27 years. He had led a "spectacularly inadequate life" and had made several suicide attempts after realising the impact his letters and tape had had on the investigation. At the age of 23 he "did not have the bottle" to confess to police.
Humble never intended to help Sutcliffe remain free, he said, but may have wanted to embarrass the police.
"He did not for one moment think the police would ultimately react to the extent that they did," Mr Bourne-Arton said. "It was not until he was to hear his voice being broadcast over the television that he became so aware."