Peterson: 'No idea' why polygraphs questionable

A former Bolingbrook police officer says he doesn't know why a polygraph shows he was deceptive in answering questions about his wife's disappearance.

Drew Peterson denies any wrongdoing in the disappearance of his wife, Stacy.

He took two lie detector tests for an upcoming book. They indicated he'd been "deceptive" in answering three questions.

The questions focused on the last time Peterson saw his wife, whether he knows where she is and whether she told him she was leaving.

Peterson told CBS' "The Early Show" Monday that he doesn't know why the polygraph shows he was being deceptive.

He says Stacy left him for another man.

Peterson's attorney says he doesn't think polygraphs are reliable but that Peterson's show he hasn't done anything wrong.