10 Things Everyone Always Gets Wrong About Batman
5. He's Never Killed

To be clear: Batman does not, and never will (intentionally), take another human's life. It's not in his MO, and it's a tenet as enshrined in his crimefighting manifesto as his commitment to never wielding a firearm.
That does not mean, however, that he's never taken a life. And while the proto-fascist inflections of Zack Snyder's Dark Knight would perhaps intimate that the Caped Crusader is a killing machine, the reality lies somewhere in between. Killing is the exception - not the norm.
When the character first started out in pre-Crisis continuity, Bats killed on a regular basis. He even wielded a firearm from time to time, and, even then, there are later instances where the Bat has tangoed with death. He left KGBeast in a barricaded sewer with nowhere to go, accidentally pushed some crooks into a garbage grinder as late as the eighties, and the less that's said about All-Star Batman and Robin, the better.
Theories also abound in regards to the ending of The Killing Joke, where Batman seemingly kills Joker in its closing moments. Whatever your thoughts on its ending, it's clear as day for all to see that, while the Dark Knight values life, he's taken more than one under dire circumstances.