While the technical sophistication of today's polygraphs is far beyond the cathode-tube stuff of the 1920s, many lawyers and judges continue to view them as inherently unreliable and overly prejudicial. Their concern is that the procedure does not test whether a subject is telling the truth but measures physiological responses to questions- which may reveal much, but not necessarily the truth. But this fall, the U.S. Supreme Court will consider, in United States v. Scheffer, No. 96-1133, whether to finally lift the barrier to admissibility of polygraph evidence, at least in the federal courts, on grounds that it inhibits the constitutional right of criminal defendants to present their defenses.
Richard C. Reuben,
Moment of Truth, 83 ABA Journal 38
Available at: https://scholarship.law.missouri.edu/facpubs/840