Hoping for half of the world's population to be killed, followed by the need for another beer is a random ass combination.
Dahmer didn't say, "That was some great 'Abducted Man Chili'" and run to the local bar.
Gacy didn't strangle a random boy, bury it in his crawlspace and be like, "It's Miller Time."
I'm gonna have to deduct 100 points for lack of serial killer motivation.