The documents were unsealed during court proceedings in Washington, where Steven Powell appeared on Friday. Steven Powell, the father of Josh Powell and father-in-law to Susan Cox Powell is accused of child pornography and voyeurism.
Steven Powell was arrested and charged after West Valley City Police detectives severed a search warrant at his home in connection with the investigation into the disappearance of Susan Cox Powell on December 6, 2009.
The search warrants include documents from West Valley City Police investigators and details about evidence they found in late 2009 and early 2010 at Josh and Susan's home and a safe deposit box accessed only by Susan.
Inside the safe deposit box, police found a "last will and testament" from Susan in which she claimed she was having marital troubles with Josh, and that he'd threatened to kill her if she ever left him.
The affidavit also said that Susan did not trust Josh, and that if she were ever found dead, "...it may not be an accident, even if it looks like one."
The documents also detail some of the initial investigation of Josh Powell on December 7, 2009, the day after she disappeared. The affidavit showed that Josh often changed his story about where he was and what he was doing during the time that Susan went missing.
Investigators said that on the day after Susan disappeared, Josh was called by a family friend early in the afternoon in which he was informed that Susan was missing. The document said that Josh claimed he was driving around West Valley City, but that he did not show up at his home to speak with police until 4 hours later.
The documents noted something else that caught investigators' suspicion. When Josh was told Susan has not shown up at work, he acted surprised, but Susan's friends knew that the Powells had only one vehicle, and that Josh took Susan to work most days.
The affidavit also showed that Josh had Susan's cell phone with him in his car when he showed up at the home the day after she disappeared and that the sim card had been pulled from it.
Police also obtained an encrypted hard drive from the Powell residence. Police stated in the documents that the hard drive contained over one terabyte of information that cannot be accessed. Police asked Josh Powell for the encryption password but Powell said he was unable to remember them.
During a news conference, WVC Police Sgt. Mike Powell said that Josh was very uncooperative during the days that followed and did not surrender his cell phone to investigators until 4 days after the disappearance. Sgt. Powell also said that when Josh surrendered his cell phone, the sim card was also removed.
Sgt. Powell also shared details about Josh's behavior after he surrendered the family minivan to investigators on December 8, explaining how he bought a new cell phone, rented a car from the Salt Lake International Airport and drove more than 800 miles in the next two days. Records show that Josh activated the cell phone in or near Tremonton, Utah before returning the car on December 10, 2009.
Sgt. Powell also said that between December 14th and 17th, Josh took his sons out of day care, canceled Susan's medical appointments, obtained power of attorney over Susan and emptied all her IRA accounts.
Sgt. Powell also detailed part of the questioning of Charlie Powell, the oldest son of Josh and Susan, on December 8. Charlie told police that "...his mommy went camping with them although she did not come back with them, and he did not know why."
Sgt. Powell also said that blood was found inside the WVC home that matched Susan's.
Investigators also said that Charlie told an LDS primary teacher in Puyallup that his mother was dead after Josh moved the boys in with his father in Washington in January of 2010.
Josh Powell killed himself and his two sons in a bloody and violent house fire on February 5, 2012. Susan Powell has still not been located. Police have conducted a number of searches in remote areas outside of Salt Lake City but have not located any remains.
The unsealed documents also reveal details about evidence seized at Steven Powell's home, including images of child pornography and several photos and videos of Susan, that investigators claim appeared as if they were taken without Susan's knowledge. Some of the photos were of Susan in her underwear as she slept or was inside a bathroom.
Police said that the evidence proved Steven Powell had a sexual obsession with his daughter-in-law, and that they found on picture in which Steven was seen masturbating to an image of Susan.
Prosecutors allege that Steven Powell took clandestine pictures of young women between the ages of 7 and 12 in his neighborhood in various states of undress, including nude.
Stay tuned to ABC 4 News and ABC4.com for more on this story.