The question of whether Batman kills or not is one of the key moral quandaries in comics. Though it feels like his “No Killing” rule is a concrete part of his character it’s actually something which has shifted, evolved, and changed since the earliest days of his creation.
The debate has been reignited thanks to Zack Snyder’s recent profanity-filled comments about superheroes which included the line, “Someone says to me: Batman killed a guy. I’m like, ‘F**k, really? Wake the f**k up.'” As Snyder here implies Batman has and will always kill, we thought it would be a good time to look back at the history of the Caped Crusader and his stance on killing.
Source: IGN.com Does Batman Really Have a 'No Killing' Rule?