KILLER IS STABBED 17 TIMES; EXCLUSIVE Con scarred for life in cell attack.
John McGeechan was scarred for life in the sickening assault in Shotts Prison, Lanarkshire.
McGeechan had staples and stitches put in his face and body after being treated in Crosshouse hospital in Ayrshire.
The heroin addict was attacked as he slept on a bunk bed in his cell.
A prison source said: "No one is shedding any tears over McGeechan but the bosses in the prison have ordered a big investigation.
"His cell was covered in blood and he was in a right mess - they've patched him up but he'll be scarred for life.
"McGeechan is saying he doesn't know who did it and there will be no shortage of suspects given his past crimes."
The so-called "snowball killer" was ordered to serve at least 20 years behind bars for murdering Amjid Ismail, 34, during a botched robbery in Maybole, Ayrshire in November 2006.
He knifed Amjid eight times in the attack and fled the shop with his victim's mobile phone.
The jury that convicted him later learned that he had a previous conviction for culpable homicide for a 1996 killing.
He stabbed 24-year-old Martin Siegerson to death for throwing a snowball at his dog in Cranhill, Glasgow - the attack which gave him his nickname.
The jail assault on McGeechan took place last month after prisoners' cells had been opened to let them carry out morning duties.
Prison officers only found out about the incident when they discovered the blood-stained glass jar on the landing.
They carried out a search and found McGeechan lying prone on a bed in his cell.
After being treated for his injuries at Crosshouse, McGeechan was sent back to the jail.
The Scottish Prison Service said: "We are unable to comment on individual cases."
Last night Strathclyde Police said: "Officers are investigating an incident within Shotts Prison in September. A report into the circumstances will be sent to the Procurator Fiscal in Hamilton."
Scarred: Killer John McGeechan was stabbed during an attack in Shotts Prison