McCann was imprisoned during the 1970s for firearms offences. While being held in H-Block 3 of the Maze, McCann befriended Kieran Nugent and participated in the blanket protest.[3]
In June 2006, McCann was charged with assault and disorderly behaviour following an incident in west Belfast. The incident occurred as the PSNI attempted to arrest a teenager for attempted robbery. However, McCann claimed heavy-handedness by the police and stated "I tried to put myself between one of the officers and the girl when the police officer radioed for assistance." McCann was released on bail.[5][6]