Susan Powell and Kids
Susan Powell's sister, Denise Cox, said that she not only believes Josh Powell killed her, but that he cooked a poisoned dinner for her before dumping his body in a nearby mineshaft. Reuters

Susan Powell's sister, Denise Cox, said that she not only believes Josh Powell killed her, but that he cooked a poisoned dinner for her before dumping her body in a nearby mineshaft.

Before she went missing, she told me that Josh cooked dinner for the family. I didn't think much of it at the time, but he never did that, she reportedly told the National Enquirer. He believed women are inferior and should always be the ones to cook and clean.

Susan went missing in 2009. Her husband told authorities that he took their sons on a camping trip. Her family believes she is dead, but her body was never found, reported the Daily News.

On Wednesday, Kirk Graves said he believes Steven Powell, Josh's father, was also behind Susan's death. Graves is married to Josh's sister, Jennifer.

I believe that at a minimum Steven knew something about what happened to Susan he said according to RadarOnline.com. At the very least, Josh told him what he did.

Steven Powell, who was arrested for possessing child pornography, is also listed as a person of interested in Susan's disappearance. Graves told authorities that Susan was a threat to Steven's power over the family.

It was a very controlled relationship. Steven controlled Josh so if he was in trouble he would have known what was going on, or even worse, been controlling what he did, Graves said. She was a threat for his control over the family. She was too strong to have around,

Susan's father Chuck Cox plans to hold a public meeting on Thursday calling for a review and an investigation into his daughter's disappearance and into the possible failing of the child-welfare department that could have led to the death of his grandsons, reported Fox News.

We're coming up with some things that should have been done differently, Cox said.

Previous reports indicate that the children began to speak out more about their mother's disappearance on Dec. 7, 2009.

Attorney Steven Downing said that Charles Powell, the oldest of the boys who was 4-years-old at the time of his mother's disappearance, began to discuss new details about the camping trip over two years ago.

The oldest boy talked about that they went camping and that mommy was in the trunk. Mom and dad got out of the car and mom disappeared, reported Dowling, according to ABC.

Earlier this month, Josh Powell allegedly Powell killed himself and his two young sons after blowing up a house he had pretended to live in.

I'm sorry. Goodbye, wrote Powell in an email to his lawyer, before allegedly blowing up his own house, reported CNN. The Pierce County Sherriff's office believes that the Powell intentionally destroyed his house with him and his children inside.

This was all on him, said Ed Troyer, spokesman for the Pierce County Sherriff's office. He set this up. He did it.