Floyd Lawton will likely be the lead in Suicide Squad (similar to Star-Lord in Guardians of the Galaxy for example), and the hired assassin has a storied history in the DC Comics Universe.
He uses a variety of weapons, including two wrist mounted guns which have become a staple of his appearance over the years. His main goal is to kill Batman and he’s tried to take out the Dark Knight a number of times with little success. His skills as a marksman and his disregard for human life serve to advance the Suicide Squad’s goals, and it’s his desire to die in spectacular fashion which is ultimately his main reason for joining the team.
He’s not suicidal, but simply doesn’t care whether he lives or dies; going out in style very much appeals to Deadshot, and he should be a fascinating character to finally see on the big screen.