The father of Josh Powell was involved in the disappearance of
his son's wife, a member of the Powell family told RadarOnline.
Josh Powell, who was a person of interest in the 2009
disappearance of his wife Susan, killed his two sons -- Charlie,
seven, and Braden, five -- Feb. 5 in a fiery double-murder
suicide at his home in Graham, Wash., during a supervised visit.
After the deaths of his son and grandchildren, Steven Powell --
currently jailed in Tacoma, Wash., on child porn charges -- also
was named as a person of interest in the disappearance. Kirk
Graves, who is married to Josh Powell's sister Jennifer, said he
believes that Steven Powell at the "very least" knows what
happened to his daughter-in-law.  "I believe that, at a minimum,
Steven knew something about what happened to Susan," he told the
website. "At the very least, Josh told him what he did."
FLASHBACK: In 911 call, social worker says Josh Powell
'exploded' home  He added, "It was a very controlled
relationship. Steven controlled Josh, so i