The seven interrogation manuals reviewed were all relatively consistent with each other; they differentiate interviews from interrogations, present interrogation as a persuasive process, and describe procedures purported to be useful in obtaining confessions. Knowledge obtained from observations of actual police interrogation behavior, however, is currently limited. Knowledge about the success rates of the interrogation tactics used by police has expanded slightly. The two studies conducted in the last 20 years suggest that police interrogations produce at least some incriminating information in 45 percent to 64 percent of cases. In approximately 25 percent of the cases, the suspect provides a full confession; however, little is known about which tactics are likely to produce confessions. Information about success rates is geographically limited. Apparently, confessions have a moderate impact on case processing. Those who provide at least some incriminating information are more likely to be charged, convicted, and receive a longer sentence than those who do not provide such information. Additional research is required to determine whether the case processing effects of interrogation generalize to the rest of the United States. It is clear that false confessions do occur; however, there is no research on how interrogation tactics can cause false confessions. 1 table and 30 references