Sucide Bomber was a CIA agent, when Esther Drummond investigated the CIA file on Torchwood. The Suicdie Bomber shot the receptionist, when he was about to shoot Esther Jakc Harkness shot him, but due to the events of Miracle Day he did not die and he detonated a Bomb strapped to his chest.
Autopsy:
at the wreckage of the explosian, the Sucide Bomber was taken to a Hospital. His body was completly destroyed by the explosian, but he was still responding. When the body was examined, his head was cut away from the body and he was still responding.
after math: the Suicide Bomber was taken to the CIA HQ in Colorado, and he was placed in a containemnt box. It was likely after the events of Miracle Day, the Sucicide Bomber died.