Associated Press
Steven Powell, the father-in-law of missing Utah woman Susan Powell, appears in Pierce County courtroom, Friday, Sept. 23, 2011, in Tacoma, Wash.\r\n

TACOMA, Wash. — Evidence collected against Steven Powell in his voyeurism case was done so legally because police at the time were investigating the possible murder of Susan Cox Powell, attorneys argue in new court documents filed Thursday.

The 61-year-old father of Josh Powell has been in jail since September when he was charged in Pierce County Superior Court with 14 counts of voyeurism and one count of possession of materials of minors engaged in explicit conduct.

West Valley police traveled to the Puyallup, Wash., home of Steven and Josh Powell in August to serve a search warrant. The warrant was in relation to the disappearance and presumed murder of Susan Powell and sought diaries that Steve and Josh Powell were keeping in their home.

In March, attorneys for Steven Powell filed a motion seeking to have the evidence collected against him during that search thrown out, claiming the search violated his Fourth Amendment rights because it went "overboard" and was nothing more than an "exploratory, random, fishing expedition."

Thursday, prosecutors filed their response. In it, they noted that one of Susan Powell's diaries was found at her work after she disappeared. The diary started on Jan. 3, 2002, and ended on Oct. 26, 2009. She was last seen on Dec. 6. Powell noted in her diaries that she had been keeping journals since she was 8 years old and the other volumes were packed away. 

Defense attorneys argued that the nexus connecting the journals with possible criminal activity didn't exist. Therefore, the search and seizure was unwarranted.

But in their response, prosecutors argue that the missing woman's diaries "have evidentiary value and are a necessary part of the investigation" into the crimes of kidnapping and homicide.

"Her own words are useful to the investigators to possibly provide further leads and areas of investigation," prosecutors wrote. "The journals are the words of a missing mother who is the victim in a homicide investigation. She cannot speak for herself. Her journals are necessary to help police get a better understanding of her life and find out information that would help them develop further leads."

By examining the journals, police may be able to develop new leads and people to interview. "They may also lead to further suspects or clear current suspects," the response states.

Prosecutors noted in the court filing that Josh Powell was considered the "prime suspect" in his wife's disappearance.

The defense also argued that Steven Powell had been cooperative with police and even offered them a copy of the journals.

But prosecutors said Josh Powell and his father at first had tried to bargain with investigators. The Powells said they would only give up Susan's childhood journals in exchange for the most recent journal that West Valley police had found at her work, according to the court documents.

"Essentially, defendant and his son were holding the journals hostage until their demands were met," prosecutors said.

Later, the Powells told police the journals weren't available at all. Instead, they went on a media campaign, appearing on national TV news programs as well as posting scanned pages of the journals on a website.

Because of that, Steven Powell "himself made the digital media relevant" and provided a nexus between the the digital media and the crimes, prosecutors argue.

"It is a reasonable inference that the journals have been tampered with or are no longer complete. There is no guarantee that the pages digitally scanned in are still in the journal. It is a reasonable inference that the journals may have been altered," according to prosecutors.

Without seeing the journals, there was no way for investigators to tell what was still intact and what was not, they said. Thus, the seizure of all digital material in the Powell house was warranted and was not a fishing expedition, prosecutors argued.

A judge in Tacoma will hear oral arguments on the motion to suppress evidence on April 23. Steven Powell's trial was scheduled to begin May 7. He is accused of secretly photographing two neighbor girls, then ages 8 and 10, through an open window into their bathroom without their knowledge in 2006 and 2007.

Josh Powell killed himself and his two young sons at his rental home in Washington in February. Since then, there have been widespread questions and speculation about what Steven Powell knows about his daughter-in-law's disappearance. It has been noted in court documents, police reports and by family members that Steven Powell had an obsession with Susan that she did not reciprocate.

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