He got greedy - ironic, eh? . http://en.wikipedia.org/wiki/Gordon_family_(Saw)#Lawrence_Gordon

hmm...we really dont know..the movie doesnt give any clue to wherever he is..i believe that he might be featured in the upcoming SAWs...yes thats plural..lol

Maybe Jigsaw used him to set up all those 'medical' traps such as the key behind the eye and the squewers through the couple in the class-room. I wouldn't think a civil engineer would have such medical know-how.

Lawrence Gordon was a doctor and the man responsible with giving the diagnosis of cancer to John Kramer. Following John's transformation into the serial killer known as Jigsaw, Kramer targeted Lawrence to be a victim in his 'game' due to an extra-marital affair Lawrence was having with his medical student, Carla. Lawrence woke up, chained by his ankle to a pipe inside an industrial bathroom along with Adam Faulkner. Lawrence was tasked with killing Adam within a set time limit. Gordon ultimately failed but escaped the trap by sawing off his foot and crawling out of the room. In Saw V, Gordon is on a list of victims stolen by Detective Peter Strahm. A special feature in the form of a farce documentary called "Piecing Together Jigsaw," available on the unrated edition of the first film, stated that his whereabouts are unknown as of one year after the first film's events. When Lawrence is mentioned in Saw III, Jigsaw said that he had been Lawrence's patient, and Lawrence had been his. Lawrence's severed foot (still chained to the pipe) was seen in Saw II and Saw III. Also, his office door was shown in Saw II and Saw IV. In Saw III, in a flashback that took place before his game began, Lawrence was shown lying unconscious on the floor in the bathroom. In Saw V, it was revealed that Hoffman had set up Lawrence as a suspect by placing his penlight at a crime scene. Among the reports of other Jigsaw victims a file on Lawrence Gordon can be seen on a shelf with them labeled as "Potential Jigsaw Victims". Later in the film, a trail of blood can be seen leaving the entrance to the bathroom as Agent Strahm descends into the basement of the newly-renovated house featured in Saw II. When Leigh Whannell asked Cary Elwes what he thought about his character's fate on the commentary for the Saw: Uncut Edition DVD, Elwes responded with, "Let's face it, guys. He's severed his whole leg off. The loss of blood alone, even with that pathetic tourniquet he made with his shirt. It's a wrap. He's not going to get two blocks." Darren Lynn Bousman said on the DVD commentaries for Saw IV that his intent was to leave Dr. Gordon's fate an unanswered question and let fans make up their own minds