Sean Moynihan lashed out at William Bermingham with a homemade weapon at Glenochil prison, in Clackmannanshire.
Bermingham needed steristrips applied to close wounds to his neck and head after the attack and Moynihan required to go to hospital to have the weapon removed from his hand where it was embedded because of the force of the blows.
Moynihan – who was already serving a double-life sentence for two rapes – was jailed for 40 months for the attack and was told that the sentence would begin at the end of a six-year minimum prison term imposed on him in 2015 as part of an Order for Lifelong Restriction.
The judge who jailed Moynihan for the latest attack, Lord Uist, told him: “Assaults of this nature in prison cannot be tolerated as it is essential that prison discipline is maintained.”
Lord Uist told Moynihan at the High Court in Edinburgh that it was clear it was “a deliberate and planned attack” in which he used considerable force.
Moynihan earlier pled guilty to assaulting Bermingham to the danger of his life by repeatedly striking him on the head and body with “a bladed instrument” on January 19 last year.
A reporting ban was in force until the end of his latest trial at the High Court in Livingston yesterday.
He was jailed for nine years after trying to rape a 15-year-old girl in Paisley in 2008 after dragging her into bushes at a cycle path and tearing off her jeans. An investigation was reopened in 2016 after new evidence established a DNA link between Moynihan and the girl’s jeans.
Moynihan was jailed for four years for rape in 2009 after a 16-year-old girl mistook his car for a taxi after a night out. She was driven to a country park and attacked.
Following his release he raped another young woman, aged 18, at the same cycle track as in the earlier rape bid and was given an indeterminate sentence under an OLR.
While in prison he was jailed for 32 months for attacking serial killer Peter Tobin at Saughton jail.
Advocate depute Iain McSporran QC said of Moynihan’s latest victim: “It would be fair to describe the complainer, William Bermingham, as a notorious sex offender.”
Bermingham, then 19, was ordered to serve a minimum of five years in 2006 after using a homemade weapon to take a 40-year-old woman officer hostage at Polmont Young Offenders Institution where he was serving a five-year term of detention for the attempted rape of a 17-year-old girl.