A man has been arrested over the fatal stabbing of a prisoner in Mountjoy jail on Monday evening.
He is being held under Section 4 of the Criminal Justice Act 1984 in Mountjoy Garda station after he was arrested by officers in the prison this morning.
Derek Glennon (24) was stabbed a number of times by a prisoner during a scuffle on the prison's D-wing landing just before Monday evening's recess at 5.40pm.
He was taken to the Mater hospital and died a short time later.
Following the incident Garda and prison service investigations got under way. Last night Minister for Justice Brian Lenihan announced stringent new security measures and a staffing increase for the prison service.
Mr Lenihan announced that he had obtained Government approval for "significant additional staffing resources" up to a maximum of 178 posts. A drug-detection dog service with approximately 30 staff will also be put in place, with sniffer dogs and x-ray security scanners in all prisons.
