THE "Wearside Jack" hoaxer who fooled police investigating the Yorkshire Ripper into diverting their inquiry to north-east England is appealing against his eight-year sentence today.
John Humble sent three taunting letters to police and a tape claiming "I'm Jack" during the huge manhunt in the late 1970s.
While police switched their inquiries to Sunderland, Peter Sutcliffe, of Bradford, committed three more murders.
Humble, an unemployed labourer and heavy drinker, was arrested last year for a minor offence. A routine DNA sample came up as a match against saliva he left on the envelope.
The 50-year-old, from Flodden Road, Ford Estate, Sunderland, was charged with perverting the course of justice.
He was jailed for eight years at Leeds Crown Court in March after the court heard how the investigation was thrown off course by Humble's Sunderland accent.
It will be argued on his behalf at the Court of Appeal today that the length of the prison term is "manifestly excessive".
The sentence challenge will be heard by the Lord Chief Justice, Lord Phillips, sitting with two other judges in London.
The real Yorkshire Ripper, Peter Sutcliffe, was jailed in 1981 and given 20 life sentences for killing 13 women and attempting to kill seven more.