From the time of Christ through the Middle Ages, methods for detecting deception were various ordeals that assumed divine intervention to establish innocence or guilt. The first attempt to use a scientific instrument to detect deception occurred around 1895, when Lombroso applied a blood pressure instrument (hydrosphygmograph) to criminal suspects. In 1921, John Larson developed a machine that was capable of recording physiological responses to questioning during an entire examination period. The polygraph instrument and techniques have improved substantially in the past 60 years; their effectiveness depends on training in interview techniques and a knowledge of psychology and psychophysiology. Another mechanical instrument currently used to detect deception is the Psychological Stress Evaluation (introduced in the 1970's), which measures human stress by analyzing the voice. Drugs, such as sodium pentothal and sodium amytal, have also been used in efforts to obtain truth and expose deception, but their reliability is highly questionable, except to obtain supplementary information on a person's psychological makeup. Hypnosis has been used to facilitate recall and also to determine the truth and falsity of statements, but because persons under hypnosis are highly susceptible to suggestion, its reliability in exposing deception is questionable. Word association has also been used to detect deception under the assumption that a guilty person will attempt to avoid replying with words that may be associated with the crime. Certain personality tests may expose proneness to crime; however, they do not specifically score or detect lying, although the Minnesota Multiphasic Personality Inventory does have a built-in instrument designed to detect deception on the test. Interviewers skilled in observing physical, emotional, and mental manifestations of the person being questioned can pick up many clues in these areas that a person is lying. None of the proponents of the various techniques for detecting deception claim 100 percent accuracy. All of the methods must still rely on human judgments and integrity, thus remaining vulnerable to human fallibility. Seventeen footnotes and 17 bibliographic entries are provided.