Factors that discriminate among mock jurors' verdict selections - Impact of the guilty but mentally ill verdict option

A mock insanity defense trial was presented to 327 college students who were then asked to render a verdict under two conditions: with and without the "guilty but mentally ill" (GBMI) verdict option being available. Among those voting GBMI, two different subgroups were identified. With respect to their attitudes and their evaluation of the evidence, those who voted guilty when the GBMI verdict option was not available were similar to those who voted guilty when the GBMI was available. Those who voted "not guilty by reason of insanity" (NGRI) when the GBMI verdict option was not available were similar to those who voted NGRI when the GBMI verdict was available. Compared to those who would have judged the defendant guilty if the. GBMI verdict was unavailable, these jurors were more likely to believe the defendant to be schizophrenic and legally insane, and to believe the defense expert witnesses.