DOE will subject all 4,500 employees with top-secret clearance to polygraph tests (WN 5 Sep 03). How likely is it that a polygraph test will uncover a spy, assuming there is one? In 1984, with the Green River body count at 46, Gary Ridgway, who has since confessed to 48 murders, was cleared after denying he knew the most recent victim. Actually, he didn’t know any of his victims. He passed a polygraph test. If the sheriff’s office had used a coin toss instead of a polygraph (WN 18 Apr 03), it’s even odds they would have wrapped up the Green River murders 19 years ago.
See also: Polygraph Testing Less than Worthless