Plot to kill: Aspiring horror filmmaker lures victims to 'kill room' with fake online dating ads

It all starts with a rather innocent-looking dating profile.

WARNING: Some of the details you are about to hear are very graphic.

Millions of people were hooked on the hit show "Dexter," about a cop living a secret life as a serial killer.

One of those people is one-time aspiring filmmaker Mark Twitchell, who police now believe turned his TV obsession into a real-life nightmare.

Mark Twitchell may be one of the most twisted and creepy killers you've never heard of, detailing his diabolical plan for murder in a 42-page document.

In October 2008, Gilles Tetreault answered an online dating ad, only to hook up with a madman in a mask.

Tetreault barely made it out alive. But another unsuspecting man, Johnny Altinger, wasn't so lucky.

Altinger, 38, thought he was meeting up with a woman he just met on a dating site. He thought wrong.

Police say you could hear screams coming out of his garage, but no one knows for sure if they were real or fake because Mark Twitchell was so clever, he notified his neighbors that he would be shooting a movie and to disregard the screams.

Wait until you hear Twitchell's explanation of what happened inside his garage.

Believe it or not, Twitchell has posted another profile looking to meet people, this time on a Canadian prison inmates website.

Twitchell writes in part: "I've made some terrible, regrettable choices in the past and I've come to terms with the consequences. Now I seek to infuse purpose into my life. Connection is a huge part of that."

He also lists his expected release date at 2027, which is not likely since he must serve at least 25 years before he's eligible for parole.

For more about the case, visit:

The Devil's Cinema: The Untold Story Behind Mark Twitchell's Kill Room, by Steve Lillebuen