remains uncertain; the unstable ex-cop David Tapp suspects that he may be Lawrence and near the end of the film, Lawrence and Adam Stanheight are led to believe it is the hospital orderly Zep Hindle. Only at the end of the film is it revealed that the Jigsaw Killer is a terminal cancer patient of Lawrence's named John Kramer, who spent the entire time posing as a corpse on the floor of the bathroom Adam and Lawrence were trapped in. Much of John's backstory was revealed in Saw II. He had gone in for a routine medical examination when he learned from Lawrence that he was dying of colon cancer with an inoperable brain tumor. Depressed by this news, John drove himself off a cliff. He survived the suicide attempt, and subsequently began his life's "work" of testing others' will to live. Though he never encouraged the name, John eventually earned the nickname The Jigsaw Killer. In spite of the intentions he had while conducting his work, he did not consider himself to be a "killer" or "murderer" because rather than killing his victims outright, he trapped them in situations from which they could escape by inflicting severe physical torture upon themselves or by killing other victims. Despite the immense brutality of his games, John took no pleasure in the suffering of his victims, but thought that it was necessary to remind them to be grateful for the gift of life. Nonetheless, he occasionally tended to confront his victims with their sins in a mocking way. He always tried to keep an emotional distance between himself and his test subjects during his games, so his personal feelings wouldn't get in the way of his work. In Saw II, John leaves a clue to his location at the scene of a game. When the police apprehend him, John places Detective Eric Matthews in a test of his own, revealing Eric's son Daniel is trapped in a house filled with a deadly nerve gas, along with several people who, although far from innocent, had previously been framed by Eric for crimes they did not commit. John offers Eric to let his son survive if the detective simply talks to him for two hours until the game is complete. Eric eventually loses patience, and after assaulting John, he forces him to lead him to the house at gunpoint. It is later revealed that