A killer serving 20 years behind bars has admitted throwing boiling water over a man who murdered his friend in a brutal jail revenge attack.
James Wright, 27, who was jailed for the murder of Craig McClelland in Paisley, flew into a rage when David Collins was put in the cell next to his in tough HMP Shotts, Lanarkshire.
Collins had been jailed for murdering 22-year-old Kevin Bishop, a close friend of Wright's, and dismembering his body.
Wright had sworn revenge on Collins, and a court was told the murderer said "you killed my pal, you can't live next door to me and I'm expected not to do anything" following the attack.
Wright, is serving a minimum of 20 years for the killing of 31-year-old student Mr McClelland, hatched a plot for a brazen attack that saw him empty a boiling kettle over Collins.
He was rushed to hospital and treated for burns and blistering.
Wright appeared at Hamilton Sheriff Court on Friday and admitted the assault at HMP Shotts in November last year.
Wright, whose earliest release date is September 2037, was handed a 20 month term to run alongside his current sentence by Sheriff Thomas Millar.
Depute fiscal Neil Thomson said: "Both the accused and the complainer were housed in adjacent cells and during the afternoon of the day of the incident the complainer David Collins cell door was unlocked by prison staff.
"He began emerging from his cell and literally seconds later the cell belonging to James Wright was opened and he emerged in possession of a kettle.
"As he emerged he moved quickly towards Mr Collins and the contents of that kettle, which turned out to be very hot water, was then thrown over him in particular on his head.
"This caused him considerable pain and he cried out which alerted prison staff and Mr Wright was returned to his cell."
Robert Mitchell, defending, said: "There is no excuse for this but there is an explanation.
"James Wright had appealed his conviction less than six months before this and it had caused him great distress after it was not granted despite there being a decent chance of it being successful.
"David Collins is serving a life sentence but his victim was a very close friend of Mr Wright who had been killed and dismembered.
"They had been kept apart but found themselves in neighbouring cells and I'm extremely surprised these two men ended up in the same hall together and ended up in adjacent cells."
Sheriff Millar said: "Even taking into account all what has been said on your behalf, assaulting another prisoner in this manner is appalling and cannot be allowed to take place.
"I'm not going to impose anything onto your current sentence but this will no doubt be taken into account when you make an application for release to the Parole Board."
Wright caused fury after killing Mr McClelland in a random attack in July 2017.
He was on early release from jail sentence for knife possession and went on the run for six months after tampering with his electronic tag.
Prison bosses recalled him to jail but he remained free, despite his details being passed to local police officers.
He brazenly used Facebook while on the run, posting pictures for months after wrecking his tag before launching his fatal attack.
His bid to overturn his conviction was thrown out by judges last year.
Collins was caged for a minimum of 26 years, reduced to 22 on appeal, after dismembering and beheading Mr Bishop in a savage attack with a machete in a Paisley flat in 2018.
The victim's torso was found dumped in a wheelie bin outside the property.
Collins had previously killed his father, also David, in an attack with a sword.
