Aug. 9, 2012 -- The personal diaries of Steven Powell show a man obsessed with his daughter-in-law, fantasizing about and spying on Susan Cox Powell for more than a year before her disappearance.
Police released thousands of pages of police reports and diary entries that were collected during the years since Susan Powell's 2009 disappearance, in which her husband, Josh Powell, was the only named person of interest. Josh Powell denied involvement in her death. He killed their two children and himself in a fiery house explosion in February of this year.
Steven Powell, Josh's father, was found guilty on charges of voyeurism in May of this year for photographs and videos he took of young girls changing and bathing in their bathroom. He is serving a prison sentence in Washington state prison.
The documents released Tuesday include numerous journal entries referencing Steven Powell's desire and love for his daughter-in-law.
"What has driven me in the past year is primarily lust. I have never lusted for a woman as I have for Susan," he wrote. "I take chances sometimes to take video clips of her, which I watch regularly."
"How I would love to kiss those lips," he wrote later.
Powell wrote about going through his daughter-in-law's laundry and masturbating with her underwear, as well as to pictures of her and, he claimed, in her presence twice.
He also admitted to using a mirror he slipped under the bathroom door to spy on Susan while she went to the bathroom.
"The fact is, I can hardly control myself when it comes to her," he wrote, noting later that his feelings "might be considered sociopathic. I mean, who looks under the bathroom door with a mirror?"
Steven Powell previously told ABC News that he and Susan had interacted in sexual ways.
"We interacted in a lot of sexual ways because Susan enjoys doing that. I enjoy doing that," he said in August 2011.
The diaries offer a clear picture of Steven Powell's feelings for his daughter-in-law, but few clues about her disappearance.
According to Josh Powell, Susan disappeared one night in December 2009 when Josh had taken their two sons on a late-night camping trip in the Utah desert.
"There's nothing in the diary that's going to lead anybody anywhere to find Susan's body," Pierce County sheriff's spokesman Ed Troyer told ABC News affiliate KOMO. "It's just disturbing reading."