[kxwynlcm] Joker's knock knock joke

Joker has some pretty good jokes in the Joker movie.  One of the later ones is incomplete yet funny in a meta way:

Knock knock.

Who's there?

It's the police.  Your son was hit and killed by a drunk driver.

It's-The-Police-Your-Son-Was-Hit-And-Killed-By-A-Drunk-Driver who?  (This line is not said.)

It inverts the typical knock-knock joke because the punch line gets delivered by the straight man (who thinks the sentences spoken by the police are just part of a very long name).  Maybe it's even OK to omit the punch line if the audience (maybe the straight man) gets that it is a meta joke playing with the format.  Maybe referencing denial as one of the stages of grief.

A-Pimp-Named-Stickback who?