film The Lie Detector, which first aired on American Experience on January 3, 2023. Hand-held lie detector for US military A hand-held lie detector is being deployed by the US Department of Defense according to a report in 2008 by investigative reporter Bill Dedman of NBC News. The Preliminary Credibility Assessment Screening System, or PCASS, captures less physiological information than a polygraph, and uses an algorithm, not the judgment of a polygraph examiner, to render a decision whether it believes the person is being deceptive or not. The device was first used in Afghanistan by US Army troops. The Department of Defense ordered its use be limited to non-US persons, in overseas locations only. Notable cases Polygraphy has been faulted for failing to trap known spies such as double-agent Aldrich Ames, who passed two polygraph tests while spying for the Soviet Union. Ames failed several tests while at the CIA that were never acted on. Other spies who passed the polygraph include Karl Koecher, Ana Montes, and Leandro Aragoncillo. CIA spy Harold James Nicholson failed his polygraph examinations, which aroused suspicions that led to his eventual arrest. Polygraph examination and background checks failed to detect Nada Nadim Prouty, who was not a spy but was convicted for improperly obtaining US citizenship and using it to obtain a restricted position at the FBI. The polygraph also failed to catch Gary Ridgway, the "Green River Killer". Another suspect allegedly failed a given lie detector test, whereas Ridgway passed. Ridgway passed a polygraph in 1984; he confessed almost 20 years later when confronted with DNA evidence. Conversely, innocent people have been known to fail polygraph tests. In Wichita, Kansas in 1986, Bill Wegerle was suspected of murdering his wife Vicki Wegerle because he failed two polygraph tests (one administered by the police, the other conducted by an expert that Wegerle had hired), although he was neither arrested nor convicted of her death. In March 2004, evidence surfaced connecting her death to the serial killer known as BTK, and in 2005 DNA evidence from the Wegerle murder confirmed that BTK was Dennis Rader, exonerating Wegerle. Prolonged polygraph examinations are sometimes used as a tool by which confessions are extracted from a defendant, as in the case of Richard Miller, who was persuaded to confess largely by polygraph results combined with appeals from a religious leader. In the Watts family murders, Christopher Watts failed a