Paul James used makeshift bladed objects to slash the face of two victims during two violent incidents at HMP Swaleside in May 2018 and January 2019.
He was handed two life sentences on Friday 3 September 2021 at Maidstone Crown Court and ordered to serve at least seven years and two months before being considered for parole. The sentences will run alongside his current sentence.
James, aged 34, admitted two counts of grievous bodily harm with intent and two counts of unauthorised possession in prison of a knife.
At around 11.45am on Wednesday 16 May 2018 James assaulted a fellow inmate by using an improvised weapon to cut him across his face, causing a 15cm laceration.
He then attempted to hide the weapon in another prisoner’s cell which was seen by a prison officer and the weapon was recovered.
On Monday 28 January 2019 James assaulted a second prisoner once again using an improvised bladed weapon.
The victim was beckoned over to a cell where other prisoners attempted to pull him inside before he broke free but was assaulted by James. The man’s face was cut where he received two 11cm lacerations from his ear to right side of his face.
Both incidents left the victims requiring hospital treatment where they needed stitches for their injuries inflicted by James.
At the time the offences were committed, James was in prison serving a life sentence for the murder of a woman in Newcastle upon Tyne in July 2007.
As well as the life sentences James was handed two 12 months sentences for the two charges of unauthorised possession in prison of a knife which will be served concurrently.
Investigating officer Detective Constable Karen Hearn said: ‘These were vicious attacks which were unprovoked, with both victims being attacked from behind without any chance to defend themselves.
‘James has proven to be a dangerous individual who has no hesitation in inflicting serious injuries on others. We do not tolerate violence outside of prison and there is no place for it inside and he has quite rightly been held to account for his actions.’