A prisoner who slashed a gangland killer has been jailed for five years.
Paul Shields, 33, struck Raymond Anderson's head and neck with a razor blade at HMP Shotts in Lanarkshire on 22 August 2018.
The High Court in Edinburgh heard Shields attacked his victim after hearing rumours that Anderson wanted to assault him.
Anderson, 57, was once handed the longest prison sentence in Scottish legal history.
He and his co-accused James McDonald, 44, were both jailed for a minimum of 35 years for murdering Michael Lyons, 21, at the Applerow Motors garage in Lambhill, Glasgow, on December 6 2006.
The pair also shot their victim's cousin Steven Lyons and notorious Paisley-based gangster Robert Pickett during the attack.
Shields, of Coatbridge, Lanarkshire, admitted a charge of assaulting Anderson to his severe injury and permanent disfigurement.
At an earlier court hearing, prosecutors played CCTV footage of the attack.
The judge could see Shields, who was serving a four and a half years for assault and robbery, sneaking up behind Anderson and lashing out at him.
Anderson could be seen then chasing after Shields with prison officers in pursuit.
Shields was caught and Anderson was rushed to hospital for emergency treatment.
The court heard that Anderson was left with a 20cm (8in) laceration stretching from his neck to the corner of his right eye following the incident.
He also sustained a cut on the left of his scalp, down to his forehead, and another behind his left ear.
Prosecution lawyer Margaret Barron said Shields, who is currently at HMP Low Moss in Bishopbriggs, Dunbartonshire, has 11 previous convictions for violence.
In the latest court hearing, Shield's advocate Drew McKenzie said his client had became "paranoid" in the weeks leading up to the attack.
Mr McKenzie added: "He has suffered from mental health problems. He became paranoid that he was going to fall victim to an attack and decided to take the matter into his own hands."
Lord Kinclaven imposed an extended sentence on Shields. As well as serving a five year prison sentence, Shields will be supervised by the authorities for three years following his release from custody.