Joe Chill

Joseph Chilton is a minor yet pivotal villain in in the 2019 psychological thriller film Joker, a DC Comics stand-alone film based on the character of the same name, the first installment of the DC Black film series.

He is a member of the Clowns movement who is responsible for murdering Thomas Wayne and Martha Wayne, thus starting Bruce Wayne's journey to become Batman.

He is portrayed by an unknown actor.

Biography
Nothing is known about Joseph other than that on the night of the riots, he saw Thomas Wayne, along with his wife and son leaving the movie theatre and walking to an empty alley. He managed to block them in the exit and proceeded to kill both Thomas Wayne and Martha Wayne, leaving Bruce as a orphan. It is unknown why he killed Thomas; however, given what he said before shooting him, he could be someone who used to work for him at some point or he found out what Thomas did to Joker and decided to take revenge for the movement's leader.

Joe is very significant, because after he killed Thomas and Martha, their son Bruce will go on to become Batman.

Trivia

 * Unlike comic book continuity, the Clown kills Bruce Wayne's parents to make a statement, while the Waynes were killed them because for money.
 * Given his role as the Waynes' killer, the Clown is speculated by some fans to be a disguised Joe Chill, but there are no sources that prove that. The film's script just identifies the Clown simply as a "Punk".
 * Originally, the Clown wasn't going to appear in the film at all. An alternate ending for the film had the Joker himself shooting down Thomas and Martha, leaving Bruce to cry alone before turning back and killing the boy. The ending was scrapped because Bruce's murder would mean that Batman will never come to exist in the universe in which Joker takes place.