You know how they say the culprit is always the person you least expect? Actually, the culprit is quite often a person you most suspect, like a really creepy serial killer:

Still, the person who had raped and strangled the woman, Cornelia Crilley, a 23-year-old Trans World Airlines flight attendant, eluded him, and the case went unsolved.
Then last month, almost 40 years after he was assigned to the case, Mr. Donnelly, now retired, heard for the first time the name of the man the authorities now believe killed Ms. Crilley: Rodney Alcala, a photographer and a one-time contestant on “The Dating Game” who is on death row in California for murdering five people in the late 1970s.

The notion of a serial killer appearing on "The Dating Game" seemed interesting enough for me to look up, and sure enough, it's on Youtube. The lucky bachelorette actually selects Alcala:

I actually think you could use this concept as a sort of combined game show/reality show. The concept would be a game show in which a woman picks a date from three men, and one of them is actually a serial killer. It may sound tasteless now, but in about five years it will be tame compared to what's on television.