"In an interview yesterday, Redden said Westerfield was the only person who failed a polygraph test during the investigation into Danielle's disappearance. Both of the girl's parents, Brenda and Damon van Dam, passed the test, as did the four friends of the van Dams who partied with the couple on the night the girl vanished from her bedroom.
Westerfield's son, Neal, also passed the polygraph test."
http://www.signonsandiego.com/news/metro/danielle/20030109-9999_1m9david.html
A polygraph is as reliable as a Newark (NJ) stripper. A series of them as reliable as her "extended family"