Police in West Valley, Utah, after announcing they had closed their investigation into Susan Powell's disappearance, released letters Monday that Powell wrote from prison to his daughter, Alina, and son, Michael, The (Salt Lake City) Deseret News reported. Powell is in prison after being convicted of secretly taping women and girls in his neighborhood in Puyallup, Wash.
Susan Powell disappeared in December 2009 from the home she shared with her husband and their two young sons in West Valley. Investigators believe Josh Powell killed his wife with help from his brother, Michael, but have never found her body.
After losing custody of his sons to his in-laws, Josh Powell blew himself and the boys up in February 2012 at his home in Graham, Wash. Michael Powell took his own life this February.
In letters to Alina and Michael in December, Powell said he would sue law enforcement for Josh's death once he was released.
"The egg flowing down the faces of the government will be massive, I believe. They must be held accountable!!!" Powell wrote. "I want them to think twice next time they decide to attack an innocent family."
In a letter to Alina immediately after Michael's suicide, Powell said FBI agents had threatened his son would have a "psychotic episode" like Aurora, Colo., theater killer Jared Holmes.
"You and I both understand the second threat against Michael as a plan to somehow assault him with psychotropic drugs," he wrote.
Powell appears to be eligible for release from prison but authorities in Washington said he failed to meet a deadline to submit an early release plan that would give information on his proposed living arrangements and plans for continued treatment.