Fortunately I'm one who has never had to kill someone but I know what I can shoot. I'm a good sized guy at 6'2" and around 200#'s. My 'go to' gun is a 9mm full of Black Talons. Why? Because I can control it better than a 1911 or .44 Mag. which have too much muzzle jump for follow up rounds.
13 rds. accurately placed or maybe one or two from a hand cannon, the choice is yours.