Although the capacity to use force still remains central to police law enforcement activities, its importance has been increasingly rivaled by the use of deception. There have been several reasons for that. For one thing, it is no longer permissible to use third-degree tactics to elicit information and confessions from criminal suspects, and the measures adopted in many jurisdictions to ensure that coercion is not used have made it much harder to employ surreptitiously. Although verbal statements and confessions are still, and will surely remain, admissible as evidence, there is little doubt that the courts have put increasing pressure on prosecutors to supplement their cases with “hard” material or physical evidence. In many cases that is not easy to do: The offenses do not involve “witnesses” (as is the case with much white-collar crime) or the witnesses are not complainants (as is the case with vice). So, over the past forty years police investigators have placed an ever greater reliance on deception as a means of accessing both material and verbal evidence.

At first the deployment of deceptive tactics occasioned some misgivings.