VIDEO: Susan Powell, missing Utah mom, documented assets in case "something happens"

(CBS) SEATTLE - Police in Utah said this week they were closing their investigation into the disappearance of Susan Powell and released their case file, including a disturbing video made by the missing Utah mother more than a year before she vanished.

Powell disappeared from her home in December 2009. Her husband, Josh Powell, was a focus of the investigation until he killed himself and the couple's two children last year in an explosive house fire in Graham, Wash.

"[I'm] covering all my bases, making sure that if something happens to me, or my family, or all of us - that our assets are documented," Susan Powell says in the video made on July 29, 2008, 17 months before she disappeared.

In the video, while documenting her belongings, she indicates a troubled relationship with her husband and makes note of her broken CDs she says he broke during an argument.

"Hope everything works out and we're all happy, and live happily ever after -- as much as that's possible," Susan Powell says in the video as she rolls her eyes.

A letter Susan Powell kept in a safety-deposit box was also released from the case file. In the letter, she explicitly writes that her husband, Josh, was not allowed to see it.

She also claims Josh threatened her if she ever sought a divorce.

"There will be no lawyers, only a mediator and I will ruin you," Susan said Josh told her.

"You, [Susan], would be destroyed and your life would be over. And the boys will not grow up with a mom and dad," Josh reportedly said to her, according to the letter.

Susan also seemed to foretell that something bad was going to happen to her.

"If I die, it may not be an accident - even if it looks like one," she wrote.

After Josh killed himself and the couple's children, investigators turned their attention to Josh's brother, Michael Powell, who, they now believe, helped Josh Powell dispose of Susan Powell's body. Michael Powell committed suicide by jumping off a parking garage in Minneapolis three months ago.

Steve Powell, Josh's father, was also a part of the investigation into Susan's disappearance and was found to have had a sexual obsession with her. While police say they do not believe he was directly involved in the disappearance, they say he may know more about it than he has let on.

Steve Powell has been serving time in prison on voyeurism charges for secretly recording images of young neighbor girls. He was sentenced in June 2012 to 2 1/2 years in Washington State prison and could be released soon based on sentence reductions he earned in prison.

Police said both Steve Powell and Michael Powell were uncooperative in their investigation.

Susan Powell's remains have never been found.

Complete coverage of the Susan Powell case on Crimesider