Josh Powell wasn't the only man creating havoc in Susan Powell's life. She told friends her father-in-law, Steven Powell, made a pass at her and tried to fondle her chest.
Susan Powell's friends told "20/20" that Josh Powell didn't defend his wife against his father.
"They had a very heated argument about Steve where she was talking about him and Josh would kind of excuse him, [saying], 'That's just my dad. You're blowing things out of proportion,'" Oreno said.
Josh Powell himself may have suffered at his father's hands.
Documents obtained by "20/20" from Steven Powell's 1992 divorce from his wife, Terrica Powell, paint a disturbing picture of Josh Powell as a severely troubled teenager under the thumb of an abusive father.
Terrica Powell wrote that Josh was exposed to pornography by his father at a young age, that he once tried to commit suicide during his early years and, most shockingly, he threatened his mother with a butcher's knife after she asked him to do the dishes.
She said Josh Powell's father had "explosive behavior" -- including severe spankings -- that hurt the son. Yet, the teen also sought his father's attention and approval.
Terrica Powell declined a request for an interview.
Josh Powell claimed his wife had her own faults. In a 2011 interview with "Good Morning America," he accused her of erratic behavior and said she once left the house in her underwear.
He defended himself, too.
"People who know me know that I'm a good dad," he said. "I work hard. I put my sons first. I was a good husband. I took care of my family."
Still, years after his parents' marriage collapsed, Josh Powell was facing the meltdown of his own relationship.
Before Susan went missing in 2009, the couple had begun counseling, said Graves, but it wasn't going well.
"It was clear to the counselor that there was no progress being made," Graves said. "Josh wasn't doing his part. And so the counselor was frustrated, Susan was frustrated. They weren't getting anywhere."
Graves believes that Susan Powell was finally ready to call it quits.
"I think her intent was that they were going to get a divorce," she said. "If this last-ditch effort of counseling didn't work, they were gonna get a divorce."
Susan Powell was reported missing Dec. 7, 2009, in Utah. Josh Powell was the only named person-of-interest in the disappearance, but he was never charged. He continually denied involvement in his wife's disappearance and later moved himself and his sons to live with his father in Washington state.
The couple's two sons were placed in the custody of Susan Powell's parents after Steven Powell was arrested on charges of voyeurism and child pornography in September 2011. Steven Powell has denied the charges.
A judge ruled earlier this month that Josh Powell could not have custody of his sons until he underwent a psycho-sexual evaluation.
Powell attacked his sons with a hatchet before igniting an explosion in his home last weekend, killing himself and his boys, officials have said. Powell locked a social worker out of the home before the explosion.