The diaries of Steven Powell paint an unsettling picture of a man sexually obsessed with his daughter-in-law, Susan Powell, for years before she vanished.
One year ago, Steven Powell claimed that he had been involved in a sexual relationship with Washington State woman Susan Powell, who was reported missing from Utah in December 2009 and has not been seen since.
The 17 spiral-bound notebooks, dating back to January 2003, reveal that Steven was fixated on Susan, according to the Salt Lake Tribune.
"I have never lusted for a woman as I have for Susan," he wrote.
"I can hardly control myself when it comes to her."
His obsession went far beyond simple fantasy. Steven Powell's diaries include accounts of snooping through Susan's possessions, stealing her underwear for masturbation purposes, and even sliding a mirror under the bathroom door to spy on her, according ABC News.
Steven Powell went so far as to buy a new house just in case Susan decided to leave his son, Josh, for him. Steven agonized over whether his 31-year age difference with Susan was the reason that she was not interested in him, and he saved newspaper clippings about love spanning disparate ages, the Tribune reports.
In the diaries, Steven acknowledges that his behavior "might be considered sociopathic" questions his own normalcy. "I mean, who looks under the bathroom door with a mirror?" he asks.
The diaries also contains numerous photos of Susan, according to KOMO News, and he described filming her in secret.
The entries stop shortly before Susan's disappearance. Unfortunately, investigators say the journals offer no clues as to what may have happened to her.
"It's just disturbing reading," said Ed Troyer, spokesman for the Pierce County Sheriff's office.
Since June 2012, Steven, 62, has been serving a two-and-a-half year sentence for charges of child pornography and voyeurism. Prosecutors say he secretly videotaped young neighborhood girls as they bathed and used the toilet.
Though Steven was initially accused of committing acts of voyeurism involving Susan Powell, those charges were dismissed because officials could not prove that she was unaware of the filming.
Susan's case was publicly declared a murder investigation in February 2012. The announcement came shorty after her husband, Josh Powell, attacked their two young sons with a hatchet before setting his home on fire in a blaze that killed them and himself.
Josh had been the only person of interest in the case, though he was never arrested or formally charged.