Paramilitary activities
Fleming became a member of Na Fianna Éireann during his early teens and later joined the IRA when he turned 17.
On 6 December 1984, Fleming and Doherty were riding around on a motorbike in the grounds of Gransha Hospital, approximately four miles from Derry city centre. The hospital was also the administrative headquarters of the Western Health and Social Services Board. It was reported at the time that the pair had gone to the hospital in an attempt to assassinate an off-duty member of the Ulster Defence Regiment who was employed there, and had intended to carry it out during a staff shift change at 8 a.m. The SAS were aware that an IRA operation had been planned to take place in the vicinity of the hospital after receiving a tip-off from an intelligence source. An SAS unit from the Derry Detachment of 14 Intelligence Company, without the knowledge of the Royal Ulster Constabulary or the hospital authorities, located troops at the site keeping watch for two weeks prior to 6 December. However, they had minimal prior information as to how the attack was to be executed and when.
At 8 a.m., Fleming and Doherty were spotted on the motorbike by the SAS sentries who were located within an unmarked car, which proceeded to ram it, dislodging Fleming from the pillion seat and causing the motorcycle to go out of control. Fleming was then approached by two other SAS troopers who opened fire and killed him, claiming subsequently that he was armed and they considered him a direct threat. The motorcycle meanwhile had struck a kerb and thrown Doherty to the ground, where he was opened fire upon by the British Army soldiers and also killed. Subsequent forensic evidence showed that six bullets struck Doherty whilst he was on the ground, and Fleming's autopsy showed that he had four gunshot wounds to his head and 56 to his trunk and torso. During the inquest into the shootings, the coroner stated that Doherty had three gunshot wounds to the head and a further twenty one shots to his body.