Tim Burton's version of Batman has Jack Napier as the shooter of Thomas and Martha Wayne. Jack Napier, of course becomes The Joker years later after an accident at Axis Chemicals (in the 1989 Tim Burton adaptation).
Joe Chill is revealed in Batman #47 (June-July 1948) as the mugger who murdered the Waynes.
Batman's origin story was first established in a sequence of panels in Detective Comics #33 (November 1939) and later reproduced in the publication Batman #1 (Spring 1940). The mugger, however, was not given a name until Batman #47 (June-July 1948). 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.
I understand that filmmakers want to have their own creative stamp on their work, but, this is a major event in the Batman/Bruce Wayne story that completely strays from the original story line of the comics.
Is there a reason that filmmakers chose to portray Jack Napier as the shooter instead of Joe Chill? Is there any evidence on who actually created the idea of Jack Napier being the shooter and then later becoming The Joker?