The man who admitted being the notorious hoaxer in the Yorkshire Ripper murder case more than 25 years ago pleaded guilty today to perverting the course of justice.
John Humble (50) was responsible for sending three letters and an audio tape which goaded police for failing to catch the serial killer, who murdered 13 women between 1975 and 1980.
The hoaxes diverted resources from the hunt for the real killer, lorry driver Peter Sutcliffe, who was jailed for life in 1981 for the murders.
Humble confessed he was the hoaxer in February but had continue to deny four counts of intending to pervert the course of justice.
He decided to change his plea before his trial was about to start today and is due to be sentenced tomorrow.
The Yorkshire Ripper case is one of the most high-profile in British criminal history and the hoaxes, which Humble started in 1978, were one of its most sensational elements.
Sutcliffe had already killed 10 times when Humble sent his tape to the police in 1979, mocking the chief investigating officer who he said was "no nearer to finding me now than four years ago when I started".
Police were criticised for falling for the hoax and moving resources from Yorkshire further to Sunderland in the northeast where accents matched the voice of the hoaxer, dubbed "Wearside Jack".
Detectives questioned thousands of men and eliminated those without a Wearside accent.
Sutcliffe, who was interviewed by police on numerous occasions, did not have such an accent. But he was finally arrested in January 1981 after police found him with a prostitute in a car with false registration plates.
PA