It could be said that Joe Chill is one of the most important characters in Batman’s history. Chill is the guy that attempted to rob the Waynes and ended up killing both of Bruce’s parents. This resulted in Bruce vowing vengeance against all evil and lead him on his path to becoming Batman.
In the pages of JUSTICE LEAGUE in The Darkseid War, Batman has gained access to the Mobius Chair. This allows him to find out whatever he wants and takes him wherever he might wish to go. In JUSTICE LEAGUE: THE DARKSEID WAR: BATMAN, we see just how far Batman is willing to go with his powers. There will be some minor spoilers for the issue below.
Using his new powers, Batman visits Joe Chill, where he’s serving a life sentence in Gotham State Penitentiary. Chill has no idea what Batman wants with him. Batman takes him to Crime Alley where Chill almost starts gloating about what he did. Batman starts losing his patience and reveals his identity to Chill. He's tempted to fire an energy blast at Chill from the chair but knows that would be too easy. Chill deserves more.
He suggests letting the other inmates know that it was Joe Chill that created the Batman. Those doing time because of Batman would soon turn on Chill. Batman knows the others would make Chill's suffering nice and slow. He continues to torment Chill and freaks him out.
Before Chill has a heart attack, Batman makes him forget his identity and the entire visit. Joe is left curled up on the floor feeling completely drained.
This isn't the first time Batman has confronted his parents killer.
Way back in 1948's BATMAN #47, Batman see's Joe Chill's mug shot in connection to a truck smuggling investigation. He immediately recognizes the killer's eyes from that fateful night when his parents were killed. Batman manages to get Chill alone and confronts him on killing the Waynes.
He tells Chill since he can't prove his guilt, he'll continue to watch over him and never let him out of his sight. This rattles Joe, who then runs into the other room as soon as Batman leaves. He tells them what happened, that he killed some guy years ago and just found out the guy's son is Batman. The other men are surprised by this.
The other crooks are angered by the fact that it's all Chill's fault Batman has been causing them problems and ruining their jobs. They get so angry that they shoot him--only to realize they never found out what Batman is.
They try to find out from Chill, who is dying from the gunshot. Batman comes in and starts fighting the men, keeping them busy, until Chill finally passes. Batman then declares the case of his murdered parents as closed.
Batman is trying to stop a killer known as the Reaper. In order to stop him, Batman has found himself having to team up with...Joe Chill, his parents' murderer. He even saves his life when he almost falls off the side of a building. He vows to his father that once he's done needing Chill's help, he'll deal with him.
He finally takes Chill to the scene of the murder and reveals he knows he killed the Waynes and he's their son.
He'd been carrying around Joe's gun--the one he used all those years ago on his parents. With one bullet left in the gun, he's ready to use it on Joe. Then he can give up being Batman. As he holds the gun to Chill's head, the Reaper comes and kills him. Having overheard the entire conversation, he now knows Batman's secret. But that's okay, things don't go too well for Reaper after this.
In this Zero Hour story, Batman is time displaced and finds himself in the Batcave in the past. Strangely enough, he discovers that his parents were alive and it was young Bruce who was shot and killed.
Knowing who he killer is in this time period, he hunts down Joe Chill. He finally finds him to get another big surprise.
Joe Chill was a drug addict. He'd been wasted in his room for the past two days, when 'Bruce' was killed. Now Batman was left wondering if Chill was the killer after all.
This issue doesn't directly deal with Batman confronting Joe Chill, but we do see him after his parents were killed. Here, Bruce is brought to his Uncle Philip, who became his guardian. Because Philip Kane has to travel a lot, his housekeeper, Mrs. Chilton, will be looking after him as well.
It turns out Mrs. Chilton was very proud of Bruce. She was there when Bruce was at his parents' grave and vowed to dedicate his life to bringing their killer to justice and fighting all criminals. Years later, she she told him she knows he's kept his vow to his parents. When he wonders what she means by that, she mentions the research in crime prevention the Wayne Foundation is involved in.
The truth is, she did know his secret. She had a secret of her own.
Mrs. Chilton had two sons of her own--Max and Joe. They changed their name to Chill and became criminals. This means Bruce was actually raised by his parents' killer's mom. At least until Batman's history was changed and Alfred Pennyworth became Bruce's guardian.
Batman and Joe Chill have had other confrontations over the years. At least now, in the current continuity, we know Joe is behind bars where he belongs, probably having nightmares and getting a cold chill even though he may not fully know why.