MOSK, J.
I dissent.
A confession is voluntary when it is the product of a rational intellect and a free will. (Blackburn v. Alabama (1960) 361 U.S. 199, 208 [4 L.Ed.2d 242, 249, 80 S.Ct. 274].) If the will of the accused is overborne by the interrogation and if he would have remained silent but for the improper influence, the resultant confession must be deemed involuntary. (Bram v. United States (1897) 168 U.S. 532, 562 [42 L.Ed. 568, 580, 18 S.Ct. 183].) An involuntary confession tends to be unreliable. (Jackson v. Denno (1964) 378 U.S. 368, 383 [12L.Ed.2d 908, 919, 84 S.Ct. 1774, 1 A.L.R.3d 1205].) “These standards are applicable whether a confession is the product of physical intimidation or psychological pressure, and, of course, are equally applicable to a drug-induced statement. It is difficult to imagine a situation in which a confession would be less the product of a free intellect, less voluntary, than when brought about by a drug having the effect of a ‘truth serum.’ ” (Townsend v. Sain (1963) 372 U.S. 293, 307-308 [9 L.Ed.2d 770, 782-783, 83 S.Ct. 745].)
In its only judicial definition the drug scopolamine is described as a truth serum which causes amnesia and hallucination, gives its subject a “heightened motivation to cooperate” (United States ex rel. Townsend v. Twomey (7th Cir. 1971) 452 F.2d 350, 368) and results in disorientation from his environment. (Id. at p. 367.) In the Townsend case, scopolamine (also known as hyoscine) was administered together with phenobarbital, a tranquilizer; in the instant case it was added to Demerol, an analgesic.
The majority, in footnote 7, cite as authority a 1951 medical dictionary declaring scopolamine, to possess sedative qualities. I hope no inference arises therefrom that although statements obtained through use of truth serum are inadmissible, interrogation by police of a suspect under sedation is to be condoned.
While it may be true that generally the colloquial “truth serum” is sodium pentathol, scopolamine appears to have some of the same effects, in that the drug obtunds consciousness, producing a “twilight sleep,” and the patient has none of his conscious defenses. Unlike sodium pentathol, however, under scopolamine the tendency is to babble confusedly, in a delirium; where normally the subject might not answer, under this drug he will answer but not necessarily truthfully.
Modern medical texts describe the effects of scopolamine in these terms:
Goodman and Gilman, Pharmacological Basis of Therapeutics (3d ed. 1970), page 535: “The behavior and mental symptoms [after injection of the drug] suggest an acute organic psychosis. Memory is disturbed, orientation is faulty, hallucinations (especially visual) are common . . . and