Only a handful of cases in which scopolamine was used for police interrogation came to public notice, though there is evidence suggesting that some police forces may have used it extensively. [2,16] One police writer claims that the threat of scopolamine interrogation has been effective in extracting confessions from criminal suspects, who are told they will first be rendered unconscious by chloral hydrate placed covertly in their coffee or drinking water. [16]

Because of a number of undesirable side effects, scopolamine was shortly disqualified as a "truth" drug. Among the most disabling of the side effects are hallucinations, disturbed perception, somnolence, and physiological phenomena such as headache, rapid heart, and blurred vision, which distract the subject from the central purpose of the interview.

In 1963 the US Supreme Court said in Townsend v. Sain, 372 U.S. 293, that "serum-induced confession" was in effect a form of torture and the practice was ruled unconstitutional.

It is at least generally recognized that the administration of sufficient doses of scopolamine will break down the will. ...The early literature on the subject designated scopolamine as a "truth serum." It was thought to produce true confessions by criminal suspects. E. g., House, Why Truth Serum Should be Made Legal, 42 Medico-Legal Journal 138 (1925). And as recently as 1940 Dean Wigmore suggested that scopolamine might be useful in criminal interrogation. 3 Wigmore on Evidence (3d ed. 1940) § 998, at 642.

....However, whether scopolamine produces true confessions or false confessions, if it in fact caused Townsend to make statements, those statements were constitutionally inadmissible.

Here's another interesting fact about scopolamine, which we remember from the late 1970's, when we used to argue a chemical defense in cocaine cases: The chemical formula for scopolamine is C17H21NO4. The chemical formula for cocaine is the same- C17H21NO4. The two compounds have the same molecular formula but different structural formulas, thereby accounting for the different effects. Anyway, it's interesting that scopolamine is now being called a variation of the date-rape drug. [reuters link via Cursor.]