'Behind Mansion Walls': Susie Newsom's Shocking Story Resulted In Nine Deaths (VIDEO)

"Behind Mansion Walls" told the story of Susan Newsom, who seemed to have fallen quite literally madly in love. With two young sons, she divorced her husband Tom, only to later become intimate with her first cousin Fritz Klenner. This relationship would prove toxic to almost everyone around them.

First, Tom's mother and sister were found, shot execution-style. Then both of Susie's parents and her grandmother met their fate the same way, putting Susie at the top of authorities' suspects list. Susie's parents were killed shortly after showing support for the idea of giving Tom more custody of the couple's children.

Their story ended in a horrific car chase, but even then the truth proved elusive. With her sons in the car, Susie and Fritz were fleeing from police, with Fritz firing back at them. Then, he detonated a bomb and killed everyone in the car. Or at least, that's what it seemed at first.

After an autopsy, they discovered that Susie's sons had already been poisoned with cyanide at the time of the explosion. Even worse, they theorized that the poison must not have been working fast enough so Susie shot both of her sons in the head.

"I can’t have ‘em, nobody will," an investigator suggested.

The harrowing tale is the subject of a book and has been adapted into a made-for-television movie.

More shocking true crime stories unfold every week on "Behind Mansion Walls," Thursdays at 9 p.m. ET on ID.

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