The murder traumatizes Bruce, inspiring his vow to avenge their deaths by fighting crime in Gotham City as the vigilante Batman.

[2] As an integral part of Batman's origin story, Joe Chill has appeared in numerous media adaptations.

Chill is, in most versions of Batman, a petty mugger who kills Bruce's parents Thomas and Martha while trying to take their money and jewelry.

In that issue, Batman discovers that Joe Chill, the small-time crime boss he is investigating, is none other than the man who killed his parents.

Chill accuses him of bluffing, but Batman takes off his cowl and reveals his secret identity: "I know because I am the son of the man you murdered!

Len Wein and John Byrne add a one-panel coda in their retelling of this scene in the first issue of The Untold Legend of the Batman.

"[3] In Detective Comics #235 (1956), Batman learns that Chill was not a mere mugger, but actually a hitman who murdered the Waynes on orders from mob boss Lew Moxon as revenge for Thomas foiling one of his robberies.

Batman deduces that Chill spared his life so he would unwittingly support Moxon's alibi that he had nothing to do with a robbery that was really a planned murder.

As an adult, Bruce continues to visit her and still calls her "Mom Chilton", unaware of her connection with Joe and Max Chill.

[4] Alfred Pennyworth, the Wayne family butler, is also secretly aware of Mrs. Chilton's connection to Joe and Max Chill, but he keeps that information from Bruce.

Several Gotham City crime bosses hire Chill, an experienced button man, to kill the Reaper, a vigilante serial killer who is murdering their associates.

In Detective Comics #678, a "Zero Hour" crossover story, Batman finds himself in an alternate timeline where, instead of his parents, he was killed by a mugger.

Once he returns to his own timeline, Bruce Wayne is plagued with doubt; he wonders if there is a possibility that he never actually caught his parents' killer, and if that makes any difference regarding his crimefighting career.

[7] In 2006, Infinite Crisis #6 reestablished that Chill was responsible for killing Thomas and Martha Wayne, and that he was later arrested on that same night for their murder.

Considering the issue consists of Bruce's flashbacks and hallucinations from an experiment he undergoes during his early career, however, it is left ambiguous whether the events of the story are real.

[13] Batman, Batgirl, and the Red Hood arrive at the theater where the two Jokers are holding Chill prisoner as a film plays of Chill confessing that he killed the Waynes because he thought they were rich elitists who didn't care about anyone but themselves, only to realize that he was wrong after he saw the young Bruce sobbing over their dead bodies.