The parents of Powell, her husband Josh Powell's sister, Jennifer Graves, and Graves' husband Kirk Graves appeared on the show with Cox family spokeswoman Shelby Gifford.
Dr. Phil McGraw presented the show as a way to prompt people to consider what they would do if they suspected their loved one was killed by someone meant to care for them. He cast doubts on what he called Joshua Powell's "odd alibi," stating that his stories "don't add up."
Susan Powell has been missing for more than two months. Her husband said he last saw her just after midnight on Dec. 7, when he left to take the couple's two young boys camping in a remote part of Tooele County.
Jennifer Graves spoke of her conflicted position having a brother who is a person of interest in the disappearance of a sister-in-law whom she considers a "good friend."