David was a member of Cell 114, disguised as a human with a wife. When he was activated, he murdered his wife and then Patrick Grainger. He then planned to blow up a major military base, and killed several soldiers as he attacked it. Jack, Gwen and Beth then tried to stop him and Jack shot him in the shoulder as he was stabbed by David. He then used his sleeper bomb to kill himself as Jack, Gwen and Beth escaped. (TW: Sleeper)