The haunting true story of what happened to Debra Newell's sister in Dirty John.

Debra Newell fell fast for John Meehan. At 59, she thought she’d finally found the one.

She would later discover John was a compulsive liar, a manipulator who had a history of stalking and blackmailing women.

He was a monster, wrapped up in an appealing package.

Their twisted tale became the focus of the 2017 hit podcast, Dirty John. It has since been adapted for the small screen and it’s streaming on Netflix now.

But John Meehan wasn’t the first dangerous man in Debra’s life. Her story actually began decades earlier, with the murder of her older sister, Cindi.

Debra and Cindi grew up in a strict religious household with parents who preached about forgiveness.

Watch the trailer for Netflix’s Dirty John below.

Cindi was still a teenager when she met and fell in love with a man named Billy Vickers. After Billy proposed, they married young and started a family together.

Cindi’s family loved Billy. He seemed to be a doting husband and the perfect match for their Cindi.

But behind closed doors Billy was allegedly possessive and controlling. He closely monitored what Cindi was wearing and who she was seeing.

After 14 years of marriage and three kids, Cindi finally worked up the courage to leave Billy.

Her family was anything but supportive of the move. Her mother Arlane actually let Billy move in with her and appeared to be taking his side in the separation.

On March 8, 1984, not long after they had split up, Billy went over to the house he used to share with Cindi.

Cindi was sitting at the kitchen table with her back towards him. He walked up behind her, put a gun to the back of her head, and fired one shot.

Billy then turned the gun on himself, before calling the police and telling them, “I’ve shot myself”. Cindi was killed instantly, but Billy survived his self-inflicted wounds.

It’s what happened next that’s so surprising and disturbing.

Arlane had always adored Billy, and when he called her from his hospital bed to apologise for taking her daughter’s life, she said she still loved him.

“I said, ‘God has given that love to us for you. We love you, and we forgive you.’ And he just sobbed and he cried,” she told Christopher Goffard, the host of the Dirty John podcast. 

With Billy facing life in jail, Arlane called his defence lawyer and said she wanted to testify on his behalf.

In court, she told the 12 person jury Cindi had mistreated Billy. The jury sobbed as Arlane preached forgiveness on the stand for five hours straight.

Thomas Avdeef, the prosecutor on the case, had never witnessed anything like it.

“They threw [Cindi] under the bus,” Avdeef told the LA Times. “I don’t know the dynamics of the family. I could never understand that. Why say bad things about the victim?”

The jury acquitted Billy of first-degree murder. He then pleaded guilty to voluntary manslaughter and was given a sentence of only five years for Cindi's death.

But Arlane's testimony, good behaviour, and time already served meant Billy would only spend two years behind bars.

Arlane then travelled around the world giving talks and preaching forgiveness.

In 2004, she gave a talk at the Orange Coast Christian Outreach Week called “Forgiveness Beyond Understanding: When murder strikes close to home”.

This was the environment Debra grew up in. This was all she knew.

When John walked into Debra's life, Arlane had been preaching forgiveness at her for 59 years. And she had been defending her eldest daughter's killer for almost 30 years.

It's not hard to see why Debra was an easy target for John. She was a sitting duck, a woman who had been brought up to believe her worth was less than the man she was with, a daughter who believed forgiveness was always the best option.

The story of Debra and John started 30 years before they even crossed paths.

If you'd like to hear more from Keryn Donnelly, you can follow her on Instagram and Facebook.