"Saw - II"

Much of the character's backstory was revealed in Saw II, revealing that he had become sick and had gone in for a medical examination, where he learned from Dr. Lawrence Gordon that he was dying of colon cancer, with an inoperable brain tumor.

At this point, he stated that he began to see how many people took their lives for granted. He drove himself off of a cliff but survived the suicide attempt, and subsequently began his "work" to save people from themselves.

Though he never claimed nor encouraged the name, Kramer's work eventually earned him the nickname The Jigsaw Killer, in spite of the circumstances and intentions he had while conducting his work; he did not consider himself to be a "killer" or "murderer".

This is because rather than killing his victims outright, he trapped them in situations which he called "tests" or "games", in order to test their instinctual will to live versus physical or psychological torture.

In Saw II, Jigsaw leaves a hint in one of his traps that leads police to apprehend him. There, he puts police Detective Eric Matthews through a test by showing him Matthews' son Daniel trapped in a house filled with nerve gas, along with people whom, though far from innocent, Matthews had framed for crimes they did not commit.

Jigsaw offers to let the younger Matthews survive if the Detective sits and talks to him, which ends with Eric brutally beating Jigsaw and forcing him to lead him to the house. Upon their arrival, Jigsaw is rescued by Amanda Young, one of his victims (introduced previously in Saw) who, having survived her trap and seeing her captor as a savior, has become his apprentice.