Basically, use your twisted imagination to come up with a great serial killer shtick. Here's one.
The Coldstone Killer.
He would dress in a beekeeper's uniform and randomly select victims from the phone book. He bludgeons his victims with an ice cream scooper and scoops out the victim's eyes. Then a Coldstone Creamery business card will be placed in between the victim's front two teeth with a cryptic message written in invisible ink. The message makes no sense and has no purpose other than to throw off the police.
You try.
Here I am, bored with everything.