Comic Books
The Batman we know and love today is very different from the Batman of the 1960s, who is, in turn, very different from the Batman of the 1950s, who is, again, very different from the Batman that first appeared – courtesy of Bob Kane and Bill Finger, in 1939. As with most comic book characters that have achieved such longevity, he has become a reflection of the times – and the Batman of 1939 and 1940 was a fearsome, brutal man who was quick to mete out violent justice to those that broke the law.
In his earliest incarnation in Detective Comics Vol 1. – before his origin story coalesced – he carried a gun and killed a great many villains, including the Mad Monk. He evolved, however, and his ‘no kill’ rule soon became the thing to which fans would doggedly pin him. But, Batman is us, and sometimes we fail. Although Batman does succeed more often than not in his comic books, people do die, and he is responsible – as we can see in just a few examples from more recent times.
Batman Annual No 8 (1982)
Batman kills Ra’s al Ghul and sends his ashes into space. This was later retconned, of course, and Ra’s al Ghul returned – but reducing him to a powder and scattering him in orbit is pretty definitive.
Batman #420 (1988)
Batman locks KGBeast underground and walks away – unarguably leaving him to starve to death. This was also later retconned, but was clearly intended as a lethal action at the time.
Batman #425 (1988)
The Dark Knight unwittingly crushes a drug dealer with a stack of cars in a junk yard.
Detective Comics #613 (1990)
Batman kicks a villain during a confrontation – knocking him into another, and sending both bad guys falling into a garbage grinder. Of course, this was accidental, but he was responsible for their grisly demise, nonetheless.
All-Star Batman And Robin #7 (2007)
In a particularly grim incident, Batman burns a group of armed robbers alive, beats them down while they burn, and then leaves them to die while he hooks up with Black Canary on a nearby rooftop.
Obviously, a number of Batman comic book titles really aren’t “canon.” With over 75 years of publication history under his utility belt, there are all kinds of different takes on the character, in all kinds of alternative universes, and ‘Elseworld’ stories. The point is though that Batman kills, regardless of the canonical status of the story – therefore the idea that “Batman killing isn’t canon” is illogical.