Half the murders are probably bandits who're killed before they got their kill; read, self defense worked in the bandit's disfavor. That said, I did feel bad first time I killed someone. Then again, so far the only time I killed someone, and I did it to save myself and a friend. Some guy was running around cherno, with a dinner bell, loudly ringing it. So a lot of zombies in tow. He ran around and ran past us a couple of times (we were on the other side of a wall, at one of those crawl areas) We got scared he'd try to attack us or that the zombies would go 'n focus us. So when he got swarmed, my friend made the call, and I shot him, at the time though. He just fell down and was about to get eaten, so it was more of a mercy kill at that point. This game makes you paranoid though.