There's a bizarre new twist in the mystery of missing mom Susan Powell: her father- in-law has been arrested on child pornography charges.
The missing mom's two children, aged four and six, have been taken into protective custody.
Chuck Cox, Susan Powell's father, is now seeking custody.
"I'm trusting that the court knows what they're doing in keeping them in protective custody and I feel the children are better off not being in that home," he told reporters.
Police say they found thousands of pornographic images in a raid on Powell's home near Tacoma, Washington.
Police say the chilling videos of children as young as eight, mostly kids from his neighborhood, were secretly shot with high-tech camera equipment.
They also found disturbing images of missing mom Susan Powell, which police say were shot without her knowledge.
Susan Powell vanished without a trace two years ago, and police say the only person of interest is her husband, Josh, Steve Powell's son.
Josh Powell denies any wrongdoing.
Steve Powell shocked the nation with the claim that he'd had had a sexually charged relationship with Susan.
"I wasn't going to turn down an opportunity with this beautiful woman, even though she was my son's wife," he told the Today show.
And it was revealed he recorded several creepy love songs dedicated to Susan:
"I can love you in a secret way/
I can love you each and every day/
There is nothing I can't see/
There is nothing you can't be/
It's not perfect, but I'm missing you."
His arrest adds a bizarre new angle to the already baffling mystery.
Authorities have determined the young girls photographed all lived near Steve Powell between June 2006 and August 2007.