With the debut of NBC's "Hannibal," one more serial killer is joining the ever-swelling ranks of the once-neglected character archetype on TV. Serial killers used to be restricted to cinematic thrillers and the last few minutes of the occasional "Law & Order."

But increasingly, they're everywhere and not just on cop shows. In fact, in one case, a serial killer is the cop.

Here are a few of the most notable killers to have graced the small screen in the past few years. Some have been caught, some have paid the ultimate price and others ... well, others are still out there.