The patients were told only a few minutes in advance that narcoanalysis would be performed. The doctor was considerate, but positive and forthright. He indicated that they had no choice but to submit to the procedure. Their attitudes varied from unquestioning compliance to downright refusal.
Each patient was brought to complete narcosis and permitted to sleep. As he became semiconscious and could be stimulated to speak, he was held in this stage with additional amytal while the questioning proceeded. He was questioned first about innocuous matters from his background that he had discussed before receiving the drug. Whenever possible, he was manipulated into bringing up himself the charges pending against him before being questioned about them. If he did this in a too fully conscious state, it proved more effective to ask him to "talk about that later" and to interpose a topic that would diminish suspicion, delaying the interrogation on his criminal activity until he was back in the proper stage of narcosis.
The procedure differed from therapeutic narcoanalysis in several ways: the setting, the type of patients, and the kind of "truth" sought. Also, the subjects were kept in twilight consciousness longer than usual. This state proved richest in yield of admissions prejudicial to the subject. In it his speech was thick, mumbling, and disconnected, but his discretion was markedly reduced. This valuable interrogation period, lasting only five to ten minutes at a time, could be reinduced by injecting more amytal and putting the patient back to sleep.
The interrogation technique varied from case to case according to background information about the patient, the seriousness of the charges, the patient's attitude under narcosis, and his rapport with the doctor. Sometimes it was useful to pretend, as the patient grew more fully conscious, that he had already confessed during the amnestic period of the interrogation, and to urge him, while his memory and sense of self-protection were still limited, to continue to elaborate the details of what he had "already described." When it was obvious that a subject was withholding the truth, his denials were quickly passed over and ignored, and the key questions would be reworded in a new approach.