The man who deceived police during the Yorkshire Ripper case with false claims he was the killer has been jailed for eight years at Leeds Crown Court.
Humble, known as Wearside Jack, was trapped by DNA on an envelope
John Humble taunted detectives when he claimed to be the Ripper in three letters and an audio tape in the 1970s.
His actions made police concentrate their hunt in Sunderland while the Ripper continued to kill in Yorkshire.
Humble, 50, of Flodden Road, Sunderland, admitted four charges of perverting the course of justice.
Judge Norman Jones told him his offences were at the upper end of seriousness when it came to perverting justice.
The judge said it could not be said Humble's actions caused or directly led to the deaths of three women who were murdered after the hoax letters and tapes had moved the focus of the police investigation to Sunderland.
Nor could it be said the killer would have been caught earlier had it not been for Humble.
But Judge Jones explained that when the real killer Peter Sutcliffe was caught, he told police the hoax letters and tape had given him "confidence".
Humble's taunts made police think the Ripper came from Sunderland
He said: "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."
After the case Det Ch Supt Chris Gregg, of West Yorkshire Police, said: "Whilst the person responsible for sending the hoax - letters and tapes - remained unknown, it left a great many people with unanswered questions, in particular the families of the victims who lost their lives at the hands of Peter Sutcliffe.
"We were determined to do everything we could to find the answers to those questions and at least give some degree of comfort now that the case been closed once and for all."
Humble came to be known as Wearside Jack as his taunts to the police continued.
'Sad old man'
His identity was discovered 25 years later when his DNA, taken after a minor offence, was matched against saliva on an envelope sent to detectives.
Outside court, the son of Peter Sutcliffe's first murder victim said he was satisfied by the sentence.
Richard McCann, whose mother Wilma McCann was killed in 1975, said: "I think the families will be glad to hear of that sentence.
"I think it does bring some closure."
Asked what he thought about Humble, Mr McCann said: "I just think he's a sad old man."
Sutcliffe, 59, is serving life for the murders of 13 women in West Yorkshire between 1975 and 1981.