Forensic Science Has Not Replaced the Need For Confessions

     There is a gross misconception, generated and perpetuated by fiction writers, movies, and TV, that if criminal investigators carefully examine a crime scene, they will almost always find a clue that will lead them to the offender, and that, furthermore, once the criminal is located, he will readily confess or otherwise reveal guilt, as by attempting to escape. This however, is pure fiction.

     As a matter of fact, the art and science of criminal investigation have not developed to a point where the search for and the examination of physical evidence will always, or even in most cases, reveal a clue to the identify of the perpetrator or provide the necessary legal proof of guilt. In criminal investigations there are many instances where physical clues are entirely absent, and the only approach to a possible solution of the crime is the interrogation of the criminal suspect. Moreover, in most instances, these interrogations must be conducted under conditions of privacy and for a reasonable period of time. They also frequently require the use of psychological tactics and techniques that could well be classified as "unethical," if we are to evaluate them in terms of ordinary, everyday social behavior. [Examples of "unethical" behavior would include referring to incriminating evidence that doesn't exist.]

Fred E. Inbau, Criminal Interrogations and Confessions, 1986