The man who tried to kill Soham murderer Ian Huntley told prison officers: “I hope he’s dead, I’ve been planning this for weeks.”
Prisoner Damien Fowkes pleaded guilty to the attempted murder of Huntley in Frankland Prison in March last year.
He also admitted killing convicted paedophile Colin Hatch in a cell in Full Sutton prison in February 2011.
However his plea that the killing of Hatch was manslaughter rather than murder was accepted by the prosecution.
The judge at Hull Crown Court was told that several psychiatrists and psychologists all agreed that Fowkes has a “mixed and severe personality disorder”.
Barristers explained that the 35 year-old had “strong psychopathic traits”, and had a pathological hatred of child killers.
Huntley, convicted of the murders of schoolgirls Holly Wells and Jessica Chapman in 2003, was attacked in the healthcare wing at Frankland jail.
He needed 21 stitches to a 7ins wound in his neck after Fowkes slashed him with a homemade weapon containing a razor blade.
When told by staff he had failed to kill his victim, he said: “I wish I had.”
Colin Hatch was serving life for the abuse and murder of seven-year-old Sean Williams in Finchley in 1993.
He was strangled to death by Fowkes using ligatures made from bedsheets after he barricaded them both in a cell at Full Sutton prison near York.
Leaving the dock, Fowkes, flanked by several prison officers, looked to the media gallery and made a show of kissing the Arsenal badge on his football shirt as he was led away.
He will be sentenced for attempted murder and manslaughter tomorrow.