State Police say an inmate at the Wyoming Correctional Facility in Attica used a "lock in a sock" weapon to attack another inmate.
Terrick Terrell, 19, is charged with assault, promoting prison contraband and criminal possession of a weapon.
Police say he attacked a sleeping inmate in June. The victim suffered severe injuries.
Terrell is now being held in the Orleans Correctional Facility in Albion. He is currently serving a sentence for robbery.