Investigators also are reviewing whether any lewd images were emailed from computers taken from Powell's home, which could bring additional charges, such as trafficking.
"You sure hope that is not going to happen, but we'll see," he said.
Sheriff's deputies arrested Powell on Thursday on 14 counts of voyeurism and one count of possessing an image of minors engaged in sexually explicit conduct. Those counts were based on images allegedly taken between 2006 and 2007, but Prosecutor Grant Blinn said in a court hearing last week that images were apparently taken over a 10-year span.
Among them were photos of Susan Cox Powell, who is married to Josh Powell, Steve's son. Steve Powell has acknowledged on national television that he was in love with Susan despite her marriage to his son, feelings he also apparently discussed with his daughter-in-law and a close friend.
Susan disappeared from her home in West Valley City on Dec. 6, 2009, and has not been found despite widespread publicity about the case and numerous searches stretching from Utah's West Desert to Ely, Nev.
Powell, who had entered a plea of not guilty, is being held in the Pierce County Jail on a $200,000 cash or bond bail. Michael R. Kawamura of the Pierce County Dept. of Assigned Counsel represented Powell at the arraignment Monday.
Powell declined a request from The Salt Lake Tribune for an interview. He is currently in the county's main jail and, with the exception of his attorney, is allowed to meet with visitors for only one hour a week. Family members have already visited him, The Tribune has learned.
Troyer said Pierce County investigators have reviewed only 5 percent to 10 percent of the material seized from Powell's home on Aug. 25. Those items included computers, videotapes and photographs.
The initial charges against Powell were filed quickly and he was arrested so "we didn't have any other victims," Troyer said.
That's also why police took Powell's two grandsons, Charlie, 6, and Braden, 4, into protective custody, Troyer said.
"With what we found, the children were going to be removed," he said. "It wouldn't have been prudent to leave them behind."
He added that Child Protective Services "put them in a good receiving home."
On Sunday, Troyer sent a message on his Twitter account asking the public to "keep the heat on and get that clue or break and help West Valley close the Susan Cox Powell Case with an arrest!"
"We want to keep everybody interested and if somebody knows anything to come tell," he said. "Obviously, one strange thing leads to another in this case."
What about the kids?
In Washington, Child Protective Services typically completes its initial investigation and a juvenile judge holds a shelter care hearing within 72 hours after children are removed from a home.
But court proceedings are on two parallel tracks regarding the sons of Susan and Josh Powell.
Ed Troyer, spokesman for the Pierce County Sheriff's Department, said Monday he believes a decision has already been made to keep Susan and Josh Powell's two sons in protective custody "pending the investigation and the judge's decision" in a separate Family Court proceeding initiated by the boys' maternal grandparents. The judge presiding over that case said in a hearing Friday he would wait to make a decision after receiving the CPS report.
Chuck and Judy Cox, Susan's parents, are seeking custody of the boys and to bar their father from seeing them.
"Father is not a suitable custodian for the children," the Coxes state in their custody petition. "Mother has been missing since December 2009 and petitioners believe father is responsible for her disappearance."
Josh Powell has stated in court documents that he believes his wife freely left her family and, due to emotional instability, that it is possible she committed suicide. He stated: "I did not kill my wife. I have never abused her."
Josh Powell, who has cared for the children since his wife's disappearance and has not been charged with any crime, wants his sons returned to him.
A hearing in the custody case is set for Wednesday afternoon.