Abstract
Studies that have investigated the use of the insanity defense have revealed that the defense is rarely interposed. Few of these studies provide information on the use of psychiatric defenses other than insanity or report on how such cases were adjudicated (e.g., by trial or plea agreement). The current investigation examined all defendants who were indicted for felonies and who proffered any type of psychiatric defense in New York County (one of the five counties that comprise New York City) from 1988 to 1997. Plea, acquittal, and success rates and the manner by which cases were adjudicated are summarized. Prior research reveals that the general public believes that the defense is frequently used and often succeeds. However, in New York County, psychiatric defenses were proffered by only .16 percent of all indicted defendants.
