BOULDER, Colo. (AP) —JonBenet Ramsey's mother revealed ``the hard side of her persona'' when questioned by a detective, leading authorities to suspect she was capable of harming her daughter, author Lawrence Schiller writes in a new book on the crime.

The book, "Perfect Murder — Perfect Town," draws on nearly 600 interviews with key players in the investigation to unveil never-before reported details about the unsolved slaying of the 6-year-old beauty queen.

After Detective Tom Haney interviewed Patsy Ramsey June 23-25, police reviewing a videotape believed he had "gotten to the real Patsy," according to excerpts released by Newsweek Sunday.

"She had exhibited the hard side of her persona," Schiller wrote in the book, to be released later this week. "A side capable of bringing harm to her daughter."

When Haney told Mrs. Ramsey that she had lied to him, Mrs. Ramsey replied, "Pal, you don't want to go there. Don't start that," Schiller wrote. "The tougher the questions became, the tougher Patsy became."

JonBenet's beaten and strangled body was found Dec. 26, 1996 in the basement of the Ramseys' Boulder home, about seven hours after Mrs. Ramsey called 911 and said she found a ransom note demanding $118,000.

Police have said the Ramseys remain under suspicion in JonBenet's death, while the Ramseys have repeatedly maintained their innocence. Attorney Hal Haddon, who represents JonBenet's parents, declined comment Sunday because he had not had a chance to read the book.

Schiller theorized that JonBenet's killer was familiar with the house and knew where the family kept the blanket in which her body had been wrapped. He also revealed police evidence which was presented to District Attorney Alex Hunter on June 1-2, before the interview with Haney, according to excerpts of the book printed in the Rocky Mountain News of Denver today.

The police presentation helped convince Hunter to take the case to a grand jury, which is now hearing evidence. A spokeswoman for Hunter declined comment. The evidence included the Colorado Bureau of Investigation's conclusion that four fibers found on the duct tape that had covered JonBenet's mouth were consistent with the jacket Mrs. Ramsey wore Christmas night, Schiller wrote.

Police said the cord and duct tape used on JonBenet likely had been purchased by Mrs. Ramsey at McGuckin hardware store in Boulder, he wrote. Police also told Hunter that the fine-line Sharpie pen used to write the ransom note was one that Mrs. Ramsey had used before and was found in a cup "right beside the phone in the kitchen where Patsy always kept them," Schiller wrote.

The author said that some listening to the police presentation suspected JonBenet had wet her bed and Mrs. Ramsey had reacted violently, accidentally killing her, then she and John Ramsey covered it up.

Schiller, who assisted O.J. Simpson on his book "I Want to Tell You," and co-wrote "American Tragedy: The Uncensored Story of the Simpson Defense," also worked with Norman Mailer on his Pulitzer Prize-winning "The Executioner's Song."

"I think there will be a resolution to the case," Schiller said. "I think all the evidence will come out, but that doesn't mean someone will be convicted."

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