On Buffy and on Angel, they've been kicking around this word "murderer". So, I thought I'd do a tally.
Faith: various, including the deputy mayor, which was an accident, and that professor, which clearly was not
Andrew: Jonathan sniff
Fred & Gunn: between them, Professor Sydell
Angel: Holland Manners, et alia, by locking them in
I don't count Spike's recent rampage as he was controlled at the time.
Did I miss anybody? That's quite a lot, really.