'You have blood on your hands' - when the Yorkshire Ripper wrote to Wearside Jack in prison

Composite picture of Peter Sutcliffe, left, and John Humble, right.

Sutcliffe, who was convicted of murdering 13 women and attempting to murder seven others in 1981, wrote to hoaxer John Humble in prison shortly after the infamous Wearside Jack hoaxer was finally jailed.

Related: Story of infamous Sunderland hoaxer Wearside Jack to feature in new BBC documentary The Yorkshire Ripper FilesHumble, of Sunderland, taunted detectives when he claimed to be the Ripper in three letters and an audio tape in the 1970s.

It took 25 years before he was brought to justice thanks to DNA evidence. In March 2006 he admitted four charges of perverting the course of justice and was jailed for eight years.

In his letter, widely reported at the time, Sutcliffe blamed Humble for the deaths of his final three victims.

"You could have saved those three women, John. You have blood on your hands," he wrote.

"You could even end up in Broadmoor with me. That is where you belong."

Sutcliffe's letter was also said to read: "I have just heard that you got eight years in prison on Tuesday for the crimes you committed.

"I am not surprised that you got that length of time because what you did was very bad indeed.

"You have now had your 15 minutes of fame and you have reopened old wounds again and put me back in the media spotlight.

"I do not need this now or ever again. The same thing will happen when you are released.

"I hope you get some treatment for your problems, John, because you are very ill indeed."

However, the letter also tried to strike a friendly note, assuring him "Be strong, God will look after you," and ending"Your friend Peter."