An inmate who fractured a man's skull with a pool cue has been told his sentence for the offence will be "measured in many years".
Mark Wood, 27, of no fixed address, was in HMP Nottingham, Sherwood, when he attacked fellow inmate Earl Harrison-Turville.
Wood was unanimously convicted by a jury of causing grievous bodily harm with intent and the unauthorised possession in prison of an offensive weapon.
After the verdicts were delivered at Nottingham Crown Court, Judge Stuart Rafferty QC adjourned for psychiatric and pre-sentence reports to be prepared and will sentence on October 2.
He told Wood, who had denied both charges: "It is a sentence, I am afraid, that will be measured in many years."
The judge had told the jury in summing up: "On any view this case is a tragedy. It is going to have lasting consequences for the defendant, potentially. It certainly did for Mr Harrison-Turville."
Mr Harrison-Turville was having a discussion on his floor of the prison building when Wood got involved. Wood was on an upper floor and was leaning over a banister and saying things back to him.
The judge said: "The next things that happen are pretty clear. He (the defendant) went back into his cell and came out with a T-shirt in his hand and he was putting that on as he went down the stairs and making that movement with his arms, which the prosecution say, was 'limbering up for a fight'.
Mr Harrison-Turville had put a brush against a wall. The two men met at a pool table.
Wood - who had seven previous convictions for offences of violence - picked up the cue and turned it around, so the thinner end was in his hands.
The judge said: "The defendant says he did not say anything to Earl and he (Earl) did not say anything to me."
After striking Mr Harrison-Turville once with the cue, which shattered, prosecutor Abi Joyce said the defendant did not stop there and did it again - as the man was "prone and defenceless" on the ground.
