William Beggs (54) is currently serving a life sentence in Edinburgh's Saughton Prison for raping, murdering and dismembering a teenager in Kilmarnock, Ayrshire, in 1999.
The depraved killer from Lurgan - known as the 'Limbs in the Loch' killer - was described by police at the time of his conviction in 2001 as a "serial killer in the making".
Barry Wallace's limbs and torso were found in Loch Lomond and his head was dumped in the sea in Ayrshire. A woman walking her dog found the head in a plastic bag near Troon.
Supermarket worker Mr Wallace (18) vanished on December 5, 1999 after a Christmas night out with colleagues at a nightclub in his home town of Kilmarnock.
In 2001, a jury found Beggs took the teenager to his flat and subjected him to a serious sexual assault.
He then murdered him and used a saw and knife to cut up his body into eight pieces before dumping it in Loch Lomond and the head off Ayrshire coast.
The psychopath was jailed for life with a minimum 20 years.
The killer has become a self-styled legal expert in jail and has helped many prisoners with appeals and compensation hearings. Earlier this year it was revealed he had cost taxpayers £42,000 in legal wrangles.
Beggs has repeatedly tried and failed to have his conviction overturned at the Supreme Court.
In 2012, Beggs was awarded thousands of pounds in compensation for the length of time taken for his appeals to be heard.
The European Court of Human Rights issued a ruling that awarded Beggs €6,000 (£4,800) after finding his human rights had been breached under Article 6.1 of the European Convention on Human Rights.
The article states that "everyone is entitled to a fair and public hearing within a reasonable time by an independent and impartial tribunal established by law".
The court's ruling stated: "Although the case was complex, this did not in itself justify appeal proceedings which lasted over 10 years."
More than 10 years before he murdered Mr Wallace, sadistic Beggs had been jailed for slitting 28-year-old Barry Oldham's throat and trying to cut off his arms and legs during a camping trip in Yorkshire.
That conviction was overturned on a legal technicality in 1999. In 1991 he had also been jailed for a gruesome razor attack.
In April, it was reported that Beggs had been subject to an attack in prison. He screamed as boiling water was thrown over his face and hands in the cell attack, the Scottish Daily Record reported.
Beggs' alleged attacker was due for release this year and has since been moved to Shotts Prison. The attacker reportedly told friends he was taking revenge after Beggs attacked him soon after he arrived at the prison.