Liam McCarthy, 28, was serving a 17-year sentence at HMP Littlehey, Perry, at the time of the attack. The court heard how the guard entered McCarthys cell to complete a routine inspection before he grabbed her throat and choked her. Before other guards could intervene, McCarthy barricaded the door shut with a wardrobe and other items. Shortly afterwards, guards managed to force their way into the cell to find McCarthy shirtless on top of the victim. She was not seriously injured but was extremely shaken and upset. He pleaded guilty today to false imprisonment and causing actual bodily harm at Peterborough Crown Court. Detective Constable Tom Nuttall said: This vicious attack could have continued had the victims colleagues not intervened. Todays result means that this violent individual will not be free to harm the public for a long time.