Police allege there was an assault at the jail at 10:40 p.m. Tuesday involving two offenders who were in the same cell together.
Police say the injured man from Lower Sackville suffered life-threatening injuries and was still in hospital.
Twenty-year-old Tyrico Thomas Smith is scheduled to appear in Dartmouth provincial court on Monday to face a charge of aggravated assault as well as one count of breaching a probation order and two counts of breaching a recognizance.