SAN DIEGO (CBS 8) - The release date for a controversial new book about the Hannah Anderson kidnapping case has been moved up to Thursday. In that book, the author suggests the Lakeside teen may have had some part in the deaths of her mother and brother.

The book is called "The River of No Return: On the Trail of Jim DiMaggio and Hannah Anderson," named after the River of No Return Wilderness in Idaho, where 16-year-old Hannah was rescued.

"I'm suspicious of her behavior. I'm suspicious of her need to be in the spotlight," author Chelsea Hoffman said.

In her 290-page book, Hoffman enlists the help of criminal investigative psychologist Dr. Maurice Godwin, who estimates the time of death for 44-year-old Christina Anderson.

In an excerpt from the book, Hoffman writes:

"According to Dr. Godwin, the level of decomposition of Christina's body, as described within the autopsy report, revealed that Christina was murdered before noon on August 3, 2013."

"What I found is that the timeline of when the death occurred, between 12 and 24 hours from the time they were found," Godwin said.

Dr. Godwin says the level of Christina's decomposition confirms his findings.

"(Christina's body) was bloated and the heat has a lot to do with this," he said.

In another book excerpt, Hoffman questions whether or not Hannah was telling the truth about getting a ride to cheer camp from her mom that Saturday.

"I was wondering if Christina Anderson was dead before noon, then how could Hannah gone to cheer?" she said.

Still, Anderson's autopsy states she and her son Ethan were last seen alive on the afternoon of August 3, 2013.

In page 179, Hoffman discusses the brutality of Christina's murder, and offers some insight.

"Christina was bludgeoned to death. So why was her throat slashed through the tape that was used to keep her from screaming?"

Dr. Godwin believes it was most likely done afterwards, a sign of revenge and anger towards the victim.

"I think I put in there she may have found out something between them, confronted him and set him off," Godwin said.

Jan Caldwell from the sheriff's department tells CBS News 8 that the case is closed and that Hannah was a victim in every sense of the word, adding there has been a lot of things that have been said that are incorrect.

NBC is said to be in negotiations with Brett and Hannah Anderson to create longform non-fiction programming about the case.