Three inmates who tried to behead a fellow prisoner with home-made weapons have been convicted of murder.
Stephen Boorman, 34, was found guilty at the Old Bailey of murdering Taras Nykolyn at HMP Woodhill , a category A jail in Milton Keynes.
Jibreel Raheem, 27, had admitted killing the 49-year-old Ukrainian, while a third man, 33-year-old James Brabbs, pleaded guilty on the third day of his trial.
Prosecutor Amjad Malik QC had told jurors how the men had been allowed into the exercise yard together on the afternoon of June 5.
Boorman launched the attack by punching Mr Nykolyn in the face, knocking him to the ground unconscious.
The men then used their home-made "shanks" to slash his body and repeatedly kicked and stamped on him before tying a ligature round his neck and trying to behead him.
Mr Malik had said the men carefully planned the attack and armed themselves with the blades and a torn bedsheet.
They had smuggled one of the weapons out in a rolled-up jumper, which was not searched by prison guards, and the other was stashed between two pairs of underwear.
The attack in front of the prison guards was captured on graphic CCTV and handheld cameras.
The jury was told defendants wanted to kill Mr Nykolyn and demonstrate that they were "untouchable".
Boorman had been serving a sentence for attempted murder while Brabbs was in jail for murder and attempted murder on another inmate.
Raheem was serving a sentence for an attempted murder while Mr Nykolyn was in prison for a manslaughter conviction.
The defendants were arrested after handing over the weapons made from a miswak stick and a pencil with razor blades attached to the ends.
Boorman claimed he had been acting in self-defence, while Brabbs told officers it was all captured on CCTV so "it's not as if I can deny it".
Mrs Justice Whipple adjourned sentencing of all three defendants until Tuesday.
Detective Superintendent Ailsa Kent, of Thames Valley Police , said: "Boorman, Brabbs and Raheem clearly planned to target their victim and subjected him to a vicious and sustained attack using weapons they had fashioned themselves.
"I am satisfied that these men have been found guilty and our thoughts remain with the family of Mr Nykolyn."
