Set in the late 90s, Secrets of a Gold Digger Killer follows a waitress and mother of two, Celeste, who marries a millionaire twice her age.

Although her husband showers her with designer clothing, cars and even a house, Celeste still isn't satisfied. She ends up seducing a woman at a mental hospital, and convinces her that the only way they can truly be together is if her lover kills her estranged husband.

"It's crazy. I did so much research on Celeste. She's serving I think 30 years in prison. She's still in prison and still claims she's innocent," Julie Benz said.

Benz is known for her roles in Buffy The Vampire Slayer and Dexter, and ended up sympathizing with Celeste in order to get into character.

"When you look at the trial transcripts and you see all the evidence, I mean it's obvious that she did it. However, when I was playing her, I was on the fence. I would have days where I would be on set and I would be like, 'I don't know, maybe she didn't do it.'"

To watch the full story play out, tune into Secrets of a Gold Digger Killer Sunday, June 13th at 8/7c on Lifetime.