A lawyer for George Zimmerman, who on 26 February 2012 shot and killed unarmed 17-year-old Trayvon Martin, has told WOFL television news that his client passed a voice stress test administered by the Sanford, Florida Police Department. Criminal defense attorney Hal Uhrig made the statement in explaining why he believed that Zimmerman, whom he had not yet met, had acted in self-defense.
However, voice stress testing (of any kind) is without scientific basis and has never been proven to work at better than chance levels of accuracy. A job posting by the Sanford P.D. indicates that the specific variety of voice stress testing it uses is the Computer Voice Stress Analyzer (CVSA), which is marketed by the so-called National Institute for Truth Verification (NITV), a West Palm Beach, Florida limited liability corporation. NITV has acknowledged in federal court that “the CVSA is not capable of lie detection” (though it claims the opposite in its marketing materials).
For more on CVSA, see ABC News Exposé of Charles Humble and CVSA on YouTube.