TAYLORSVILLE -- Jennifer Graves has tried to make sense of the tragedies that have hit her family.
Her sister-in-law, Susan Cox Powell, vanished in 2009. Her brother, Josh Powell, is suspected of involvement in his wife's disappearance and murder. He ultimately killed himself and his children, Charlie and Braden, in the midst of the high-profile missing persons investigation.
"Part of me, I look at that, I think, 'Gosh, I let her down,'" Graves said in an interview with FOX 13 on Friday. "I should have done more. I should have seen this coming. I should have done more to prevent her boys being killed, I should have done more. But that the same time, I don't know what else I could have done."
Graves said she has channeled some of her feelings into a new book being released next week. "A Light In Dark Places" shares her feelings on the case and her involvement in it. She said the book has helped her heal from the tragedies she has endured.
"To a great degree, I think I've healed immensely," she said.
In the book, co-written with local author Emily Clawson, Graves details wearing a wire to help police pin her brother down about his involvement in Susan's disappearance.
"Oh my gosh, it was the scariest thing I've ever done!" she exclaimed Friday. "It felt like walking into the lion's den."
With police listening down the street to her every word, she confronted her brother, Josh, and insisted he killed Susan. Josh refused to offer any confession, but she said it solidified her belief that he had murdered his wife.
"His eyes were so dark," she told FOX 13. "They used to be blue, kind of a gray-blue. But his eyes and turned this really, really black, and it was disturbing to me. It was kind of symbolic of the evil that had infested him."
Graves had split from her family over many issues, including Susan's disappearance. When her father, Steven Powell, was arrested for voyeurism, Graves flew to Washington state to testify against him at his trial. She still believes he knew something about her sister-in-law's disappearance.
Graves said it was hard to learn that police now suspected her brother, Michael Powell, of helping Josh dispose of Susan's body.
"I don't really care that he didn't pull the trigger or use the knife or whatever himself," she said. "Actively trying to help hide her body? That's just right up there with murder."
Asked if she believes Michael Powell was involved in Susan's disappearance, Graves told FOX 13: "I don't see how I can't."
Michael Powell committed suicide earlier this year.
Graves said it was her hope that "A Light in Dark Places" would reach out to women who are in abusive situations. She realized in hindsight how bad Susan's situation was. Police revealed in search warrants that they found a "Last Will and Testament" authored by Susan Cox Powell that declared that if anything were to happen to her, for authorities to contact Graves.
"I hope that readers will be educated in some ways," said Clawson. "They will see the kinds of things that led up to Josh being the person that he was and Susan being in danger. Maybe they'll be able to look around and see someone else around them that they could help."
Clawson said she believes Graves' story shows the difficult choices she made.
"She came from the same family that Josh came from," she said. "One of them chose to escalate that type of abuse and one of them chose to completely stop it."
Graves, who has been recognized for her work combating domestic abuse, said she made a choice to protect her children from her father and others.
"I broke that chain a long time ago, and it wasn't going to take my children," she said, crying. "Unfortunately, Susan couldn't break it fast enough."
"A Light in Dark Places" is scheduled to be released next week. Graves plans to donate a portion of the proceeds from the initial sales to the Susan Cox Powell Foundation and the Chainbreakers Foundation.