It was a moment of horror that shocked America.
Now, Josh Powell’s sister, Jennifer, is speaking out about growing up with Josh in what she says was a house of evil.
She told INSIDE EDITION, “How can you do that? How can you do that to anyone, let alone to somebody that you profess to love? Josh for some reason found pleasure in killing small animals. We had multiple sets of gerbils growing up and he for some reason enjoyed killing the little babies.”
They were raised in small towns in Utah and Washington, but there were problems in the family.
She says her father, Steven Powell, wanted to be a polygamist. And he watched pornography in front of her when she was a child.
She said, “I didn't know to do? I was a kid. What does a kid do with that?”
Now, she has written a book about the case, A Light in Dark Places.
Susan Powell disappeared from her home in Utah in December 2009. Her body has never been found. Her husband, Josh, was the only suspect. Just-released interrogation tapes show he was uncooperative from the very start.
Authorities asked, “What do you want us to do? Just leave you alone and hope that she shows up?”
Josh said, “You guys are already trying to trap me on little things.”
Josh was never charged, but he lost custody of his children, Charlie, 7, and Braden, 5.
Susan's disappearance split the family, with Jennifer siding with Susan’s parents and other siblings defending their brother.
Jennifer reveals for the first time that she wore a wire and confronted her brother in an attempt to get him to confess.
Jennifer said, “I was really direct. Like, 'Where's her body. Just tell me where her body is. We want to have a funeral.'”
But the ruse failed.
She said, “He kind of played the stupid, 'My lawyer told me not to say anything.' But his emotions were just dull, non-existent. He just didn't react. It was really bizarre.”
During the investigation, her father was jailed on child pornography charges. His journal showed he was sexually obsessed with Susan and even wrote an eerie love song with lyrics like, “You let me touch you softly. Why is the question. And the effect amazes me!”
Jennifer said, “He had a humongous obsession for her so I guess it's not a huge surprise that he ended up writing weird music as well.”
She says the deaths of Susan and the boys released them from the house of evil that Josh created.
“No one can hurt them any more," said Jennifer.