Edward Scheffer (defendant), an airman in the Air Force, was charged by the court martial with using methamphetamines due to a positive urinalysis test. Scheffer claimed that he has not used drugs since his entry in the Air Force. At trial, Scheffer sought to introduce the results of a polygraph test in which he stated that he did not knowingly use drugs. The Military Rules of Evidence had a rule that categorically excluded polygraph evidence. The court martial followed this per se rule, excluded the evidence, and convicted Scheffer. The Air Force Court of Criminal Appeals affirmed. The United States Court of Appeals for the Armed Forces reversed on Sixth Amendment grounds and the prosecution appealed.