Book: Peterson's polygraph results mixed

CHICAGO, Oct. 5 (UPI) -- Former police officer Drew Peterson earned mixed results from authorities' polygraph tests following the death of his third wife in Illinois, a new book says.

Author Derek Armstrong wrote in his book, "Drew Peterson Exposed," that the former Bolingbrook, Ill., police officer agreed to take lie detector tests after authorities suspected he was involved in the 2004 death of his third wife, Kathleen Savio, the Chicago Sun-Times reported Sunday.

But Armstrong wrote that when asked questions about the October 2007 disappearance of his fourth wife, Stacy, Peterson was deemed "deceptive" on certain questions.

Peterson has maintained he was not involved in Savio's death or in the disappearance of Stacy Peterson.

Armstrong said polygraph expert Lee McCord found Peterson to have been "deceptive" on three questions, including saying "no" when asked if he knows his wife's current whereabouts.

The Sun-Times said despite the results, Armstrong says in his book that he is convinced Peterson would not have purposefully brought harm to either woman.