Kentucky adopted the American Law Institute standard for the insanity defense in 1974. While dissatisfaction with the State's provisions for the insanity defense was probably simmering for years, certain instances where mentally disturbed individuals committed violent crimes in the late 1970's provided the impetus for reform. In 1980, the Supreme Court of Kentucky recommended legislation of the GBMI statute. After considerable controversy in which the media played a major role, the GBMI law was passed in March 1982. Concern among staff members at the KCPC regarding the new law's impact on services to mentally ill inmates prompted an organized effort to gather social and psychological data on the first GBMI cases. Its results are compared with a Michigan study of all 204 male defendants found GBMI after 1975 until 1981. No GBMI cases were admitted to the KCPC during the first quarter the law was in effect, but two came in the second quarter, five in the third, and six in the last quarter. All these defendants did have diagnosable mental disorders at the time of their admission. All these disorders are potentially treatable, although most do not require hospitalization. The average GBMI case tended to be a white male in his 30's who had a history of hospitalization and arrest. There was also a tendency for GBMI defendants to be poor, without high school educations, of low intelligence, represented by court appointed attorneys, and convicted by plea bargaining. Several GBMIs told researchers that their attorneys encouraged the decision to plead GBMI, saying their sentences would be shorter. The results of this study generally are consistent with findings from the Michigan research. Recommendations for future research and footnotes are included. The appendixes contain a structured psychiatric history interview form, graphs, tables, and psychometric data.