In July, Anderson said, investigators told her they had lost that information and asked her to resend it, which may have helped lead police back to Powell's home. Chuck Cox, Susan's father, suggested Saturday that an online article about Anderson "clued" police in that "some of this existed."
West Valley City Police did not return a call for comment.
Police searched Powell's home on Aug. 25 and seized items later found to contain allegedly voyeuristic and sexually explicit images of girls and women, including Susan Powell. Police arrested Powell on Sept. 22 on 14 counts of voyeurism and one count of possessing images of minors engaged in sexually explicit conduct. He has entered a not guilty plea and remains in jail.
"I always knew Steve had a big, big porn addiction but I never thought he was a predator," Anderson said.
Anderson met Powell at a Sunstone Symposium in Seattle in the fall of 1998. She had recently left The Church of Jesus Christ of Latter-day Saints and was intrigued by theories Powell shared in a discussion group about the origins of the Book of Mormon.
They began hanging out, meeting as often as four times a month. Anderson even joined Powell at his family's home in Yakima for Christmas in 1998. A few months later, she made it clear to Powell that their relationship would never be more than a friendship.
Powell respected that, said Anderson, then a divorced mom. And their friendship, largely centered around ex-Mormon social events, continued.
By 2001 Anderson had visited Powell, then living in a previous home in Puyallup, several times. But on this particular visit, Anderson said, Powell showed her pornographic magazines and videos he kept in his bedroom. She said she quickly told him she didn't want to see more.
"He was pretty open, in an often joking way, about having an interest in porn," Anderson said.
Powell's son, Josh, had recently married Susan, and Anderson said the couple also lived in the home at the time. Powell spoke often about his new daughter-in-law, Anderson said, "about how great she was, how beautiful she was."
In 2002, Anderson met up with Powell at conference for ex-Mormons in Salt Lake City, and he was still talking about his daughter-in-law.
When Anderson asked if he was dating any one, Powell told her that Susan was "all I can think about," she said. Anderson said she commented on the fact that Susan was his son's wife, but Powell was nonplussed.
"He was hung up on her sexually, it seemed," she said. "He'd talk about trying to see under her clothing, see her breasts. Even back then, he had this idea she was flirting with him."
Anderson's contact with Powell became less frequent in 2003 when she met the man who became her husband. But they still met socially and in 2004, she invited Powell to a party at her house nearby.
"He was still talking about Susan," she said, and this time she chided him and suggested he try an online dating service.
In 2007, Anderson invited Powell to another party at her home and discovered he was still infatuated with Susan, she said. Shortly afterward, Anderson moved to Ellensburg and lost contact with Powell for a few years.
Anderson said that in the late summer of 2009, Powell called her out of the blue and they caught up on each other's lives jobs, children, relationships. Anderson said she asked Powell if he was seeing anyone. His response, according to Anderson, was that he still had "that issue of being in love with Susan."
"It was disturbing," Anderson said. "I was shocked to hear he was still hung up on his daughter-in-law."
When reports surfaced three months later of a Utah woman who'd inexplicably disappeared from her home, Anderson didn't initially make the connection. By January 2010, she realized it was Susan, Powell's daughter-in-law. Anderson said she immediately called Powell, who confirmed the news.
"I realized I at least owed a call to the police to say I was friends with this person who'd been obsessed all these years with Susan," Anderson said.
She said she spoke with a West Valley City police investigator for about an hour, but didn't hear anything from officers.
She said she heard from Powell twice after that once in April when he and Josh asked her to represent them in the blogosphere (she declined) and again on Sept. 22, 2010. Anderson said Powell called and said he was passing through Ellensburg and wanted to stop by.
The visit lasted three hours. Anderson said Powell spoke about Susan's upbringing and his theory that she ran off with Steven Koecher of St. George, who disappeared about the same time. Powell even sketched out a timeline and a map showing how their paths might have overlapped.
Anderson said when she asked if he had any text messages, phone calls or emails connecting the two, Powell pointed out that they were both Mormon and had worked in the same geographic area.
"It was like he was trying to sell me on this theory, on her being mentally unbalanced and the chance that she ran away," Anderson said.
West Valley City police and the Cox and Koecher families have said the two cases are not linked.
Anderson said Powell also brought up a police search of his Puyallup home months earlier, expressing relief that investigators had missed his "porn cabinet." Anderson said Powell told her he had lots of pictures stowed there, including some of Susan, along with seven volumes of her teenage journals.
And she said he told her this: "He said he had her [Mormon temple garment] underwear he'd stolen from a pile of dirty laundry back when they were living with him in 2001," Anderson said.
Anderson said Powell told her to visit his "Steve Chantrey" website, where he had posted songs he'd written that were mostly about Susan. And for the first time, Anderson said, Powell claimed Susan acted sexually interested in him, too claims he made himself in national television interviews this summer.
When Anderson pressed him about what he meant, Powell described brushing body contact, hugs and "even if she was looking at him, it was in a sexual way," Anderson said.
Anderson said she told Powell that a hug didn't mean his daughter-in-law was coming on to him. At that point, Anderson concluded and told Powell as much that he was misreading the situation.
When she asked Powell why he still had items related to Susan, she said he responded that he couldn't let them go because he still loved her so much.
Anderson said she was stunned, both by what Powell said and that he was sharing it with her, given their limited contact in more than three years.
The next day, Anderson once again called the West Valley City Police Department and relayed her conversation with Powell. She also faxed the three handwritten pages Powell had left with her, including his map of Koecher's travels through Utah and Nevada.
Approximately 10 months later, on July 18, Anderson said an investigator called and asked her again about the conversation; he also asked her to resend the handwritten notes, which had been lost. She emailed them to police on July 20.
Anderson shared her account anonymously this summer with the Examiner, an online news source, which published a story on Aug. 21. She has since agreed to be identified.
"I don't have anything to gain here," she said. "I just want the truth to come out about Susan. I think the Coxes deserve that."