Missing Utah mom Susan Powell, who disappeared in 2009, was apparently the target of her obsessed, divorced father-in-law, who recorded hundreds of hours of videos of her and took multiple photos, many times without her knowledge or consent.

CrimeOnline spoke exclusively with Stephanie Bauer, a seasoned investigative reporter who pored over documents, photos, and videos taken by Steve Powell (pictured second from left), which clearly showed a case of warped obsession. According to Bauer, the perverted father-in-law reportedly went as far as saving Susan’s toenail clippings, feminine hygiene products, and underwear.

The obsession reached alarming heights when newlywed Susan and her husband, Josh Powell, temporarily moved into to Steve’s South Hill, Washington, home in 2001. The recently-wed couple cordoned off the dining room privacy, but it did little to stop Steve, who, in his own mind, thought the feelings he had for Susan were mutual.

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“She just turns me on. I’m in a perpetual state of turned on when she’s around,” Steve said during one incident, while he filmed Susan folding her laundry.

In a new Oxygen four-hour series, “The Disappearance of Susan Cox Powell,” Bauer spoke with Alina Powell, Steve’s youngest daughter. Unlike the oldest Powell daughter, Jennifer, Alina believed in her father’s innocence and challenged negative things said about him.

Alina alleged that Susan herself sometimes encouraged the behavior of Steve Powell, and gave the man the impression that his advances were welcome.

Despite Alina’s claims, which can be seen in full during the upcoming Oxygen series, Josh and Susan moved out Steve’s home and found a residence in West Valley in 2004, after Susan complained to her husband that his father wouldn’t leave her alone.

After the move, Josh still maintained a relationship with his father, but it drove a wedge between him and Suan. Josh became abusive and distant to his wife each time he spoke to his father on the phone, during calls that would last hours at a time.

The abuse continued for years, until 2009, when Susan Cox Powell mysteriously vanished, leaving her children and all of her belongings behind.

In 2011, while raiding Steve’s home in attempt to find clues into Susan’s disappearance, authorities stumbled upon child pornography and hidden photos of the next door neighbor’s daughter. Steve was subsequently arrested for voyeurism and child pornography. He spent several years behind bars. He died in 2017, a year after he was released from prison.

Prior to his arrest, Susan managed to record secret audio of her father-in-law professing his love to her.

“I’ve really fallen in love with you … For the last year and a half, you’re about the only thing I could think about,” Steve said in a secretly-recorded audio.

Susan’s reply to the man may hold the clue to why she disappeared. To hear the audio recording and more about the Susan Cox Powell case, watch “The Disappearance of Susan Cox Powell,” airing Saturday, May 4 and Sunday, May 5 at 7:00pm ET/PT.

What Happened to Susan Cox Powell?

Where is Susan? It’s a question detectives have been working to solve for almost eight years.

On December 6, 2009, Susan was seen attending church at the Salt Lake Hunter Central Stake with her two boys, Charlie and Braden, ages four and two at the time. The next day, Susan failed to show up for work and her sons weren’t taken to their daycare center, according to TIME.

Josh Powell later told police that he took his boys camping at around midnight on December 7, despite the freezing weather. He said Susan stayed at home and when he returned, he couldn’t find her.

Authorities noted that Susan left behind her cellphone, keys, and wallet. Detectives suspected that Josh had something to do with his wife’s disappearance, but despite the bizarre account of him taking his children camping in the middle of the night in icy conditions, they didn’t have enough cause to arrest him.

As detectives began investigating the case, they discovered Susan also left behind trails of evidence that marked frustrations in her marriage. In 2008, she made a video in her West Valley home, in which she expressed her fear of Josh and detailed the turmoil in their marriage.

“This is me, July 29, 2008. Covering all my bases, making sure that if anything happens to me or my family or all of us that our assets are documented.”

A month prior, Susan wrote a secret note, warning people that if she disappeared, it was likely not an accident.

“I want it documented that there is extreme turmoil in our marriage. If die, it may not be an accident, even if it looks like one.”

Authorities not only had their eye on Josh, but also Steve, after they learned of his obsession with her. Police would eventually find 4,500 images of Susan on the elder Powell’s computer, all taken without her consent.

According to Steve Powell’s former wife, Terri Powell, she divorced him in 1992 after she found pornography on his computer that centered around having sexual encounters with multiple wives.

Regardless, there still wasn’t enough evidence to tie father or son to Susan’s disappearance.

Within the following years, Susan’s parents, Chuck and Susan Cox, fought desperately to gain custody of their two grandchildren, especially after Josh moved back in with his perverted father in Puyallup, Washington, after Susan disappeared, taking the two boys with him.

When police arrested Steve Powell in 2011, the Cox family filed for custody of the two boys. A Washington court judge granted them temporary custody, with the conditions Josh would regain custody of the boys if he moved out of his father’s house and into his own home, according to the Salt Lake Tribune.

Josh was also required to undergo a mental evaluation. In 2011, a psychiatrist deemed him capable of taking care of his sons. However, according to the News Tribune, the psychiatrist found Josh defensive and over-abrasive with the boys, as well possessing underlying narcissistic traits.

In turn, the court ordered that the children remain in the custody of the Cox couple, while allowing Josh visitation three days a week with his sons, supervised by a social worker.

On February 5, 2012, Josh had a scheduled visitation day with Charlie and Braden. As the social worker pulled her car up to Josh’s rental home, the children jumped out and ran to their father’s front door. Josh quickly opened the door, pulled the kids in, then shut and locked it.

The social worker, who couldn’t reach the kids in the time, started knocking on the door, asking Josh to release the kids. When she smelled gas coming from the home, she dialed 911.

The social worker spent over 10 minutes explaining the emergency of the situation to a 911 operator, but by the time authorities arrived it was too late. Josh blew the home up, killing himself and his two sons. Autopsies on the children later revealed Josh first tried to kill the boys with a hatchet before setting the home on fire.

Susan Cox Powell remains missing. Anyone with any information should contact the West Valley, Utah, authorities.

[Feature Photo: Powell Family/West Valley PD]