As years have gone by, certain aspects of Batman's character have changed here and there. The color scheme has sometimes been altered, or his outlook on the world can change depending on the writer behind him. Even the various films based upon the adventures of Batman on the streets of Gotham have portrayed the iconic superhero using a variety of difference tones and visual cues.
Despite all of these minor changes here and there, one aspect of Batman's characterization has remained consistent: he does his best to avoid killing, whenever possible. It's one of his most consistent characteristic traits across all forms of media, but might not be carried over to the version of the Caped Crusader in Batman V Superman: Dawn of Justice -- if a source close to the film is to be believed.
Batman V Superman producer Charles Roven recently explained the mentality of the film's Caped Crusader in a statement he made to Empire:
[Batman] is not giving people a chance... He is more than a vigilante. He has become not only the cop, if you will, he has also become the jury and executioner.
So it seems that this Batman may act much more ruthlessly than any other version of the character that audiences have seen before on-screen. Bruce Wayne often grapples with the struggle of whether or not to kill in the comic books. When faced with the quandary he generally refuses on the grounds that taking a life will lead him down a path of darkness that he won't be able to return from. Roven's use of the word "executioner" had led many to believe that Batman will literally kill during the movie. While that's entirely possible, the word seems to point more towards Batman carrying out any punishment he deems appropriate, rather than leaving them in the hands of the legal system.
The trailers for the film have already shown him willing to brand the criminals he hunts down with a bat symbol when he has them cornered. Such ruthless -- yet still nonlethal -- tactics seem to fit in with Roven's description of a more seasoned and cynical Dark Knight:
He’s older...[and] he’s seen the worst of what man can do. He’s been darkened by it, he’s tougher, he’s angrier, I guess... he’s still lost those that are near and dear to him, and not necessarily from old age or disease.
It's plausible that Roven's words should not be taken literally. Perhaps this Batman has grown darker by what he has encountered over the years -- and perhaps it has made him more ruthless -- but it seems unlikely that he will flat-out murder his enemies during the film. The closest possible analogue would be Frank Miller's take on the character in The Dark Knight Returns comic book storyline, which Dawn of Justice takes ample inspiration from. Within that source material Bruce Wayne is a much older, more jaded man who seemingly takes pleasure in crippling bad guys -- but he still strives to stick to his no-kill policy.
Of course, if audiences take these words literally, and Batman is indeed a killer in Batman V Superman, it's worth noting that this doesn't inherently go against the spirit of the character. In his earliest appearances the Caped Crusader often carried a gun and had no qualms against taking a life. His no-kill policy came into effect later, eventually becoming an integral part of the modern interpretation of the Dark Knight. Ultimately it seems incredibly unlikely that Ben Affleck's Batman will gleefully kill his enemies when Batman V Superman hits theaters -- particularly when one considers the backlash that occurred when Superman snapped Zod's neck during Man of Steel's climax -- but we won't know for sure until the film hits theaters in less than two months.
Batman V Superman: Dawn of Justice will be in theaters on March 25th, 2016; Suicide Squad on August 5th, 2016; Wonder Woman – June 23rd, 2017; Justice League – November 17th, 2017; The Flash – March 23rd, 2018; Aquaman – July 27th, 2018; Shazam – April 5th, 2019; Justice League 2 – June 14th, 2019; Cyborg – April 3rd, 2020; Green Lantern – June 19th, 2020.