Jason Todd was once a Robin for Batman, but his death and resurrection via the Lazarus Pit has made him a pretty dangerous individual. He doesn't have any hesitation in using lethal force so it's not a surprise that he carries guns.
Taking the mantle of Red Hood, Jason Todd goes after criminals with extreme prejudice. He's got amazing fighting skills and will not hesitate to shoot you. Red Hood is one of three fighters coming in the first DLC for Injustice 2. Check him out in action and pick him up along with Starfire and Sub Zero when the pack gets released in June.