Privacy Induces Confessions

The principal psychological factor contributing to a successful interrogation is privacy--being alone with the person under interrogation. This we all seem to instinctively realize in our own private or social affairs, but in criminal interrogations it is generally overlooked or ignored. For instance, in asking a personal friend or acquaintance to divulge a secret, we carefully avoid making the request in the presence of other persons; we seek a time and place when the matter can be discussed in private. Likewise, when anyone harbors a troublesome problem that he would like "to get off his chest," he finds it easier to confide in another person alone rather than in the presence of a third party. In criminal interrogations, where the same mental processes are in operation, and to an even greater degree by reason of the criminality of the disclosure, interrogators generally seem to lose sight of the fact that a suspect or witness is much more apt to reveal his secrets in the privacy of a room occupied only by himself and his interrogator than in the presence of an additional person or persons.

Fred E. Inbau and John E. Reid in Criminal Interrogation and Confessions, 1962