I use an "all npcs killable" mod for my roleplaying character, and disable it for my main quest character. In one quest for my roleplaying character I had to buy skooma in Bravil. I decided that my crazed crusader character would simultaneously get the skooma and kill the dealer as to cleanse Bravil of his presence. I did so in a back alley without him seeing me (indeed, I'd never been to Bravil before so we'd never seen each other ever). About a week later game time I'm sitting in an inn in Bravil chatting it up when he comes in and sits next to me, greeting me with a "good afternoon". If my character's expression was anything like mine, he must have immediately been suspicious as to the cause of his ambush and robbery a week before by an unknown assailant.
