The court decision in People v. Gibson invalidated the existing Section 2962 of the California Penal Code which mandated treatment in a facility of the State Department of Mental Health for persons who were determined to be MDO's. The invalidated MDO legislation required that persons meeting specified criteria who had been sentenced prior or subsequent to July 1, 1986, be confined in a mental hospital as a condition of parole. The Court of Appeal determined that the MDO law made it potentially possible to retain a person for life in a State hospital without proof of grave disability or dangerousness resulting from mental illness. The court also held that the law violated the equal protection clause of the 14th amendment in not requiring proof of any present dangerousness resulting from mental disorder. At the time the court decision became effective in 1989, 171 cases determined to be MDO's were receiving treatment in Department of Mental Health facilities and programs as a condition of parole. Of these cases, 156 were in hospitals and 15 were under parole supervision in the community. The Gibson decision made all 156 MDO cases eligible for release to community supervision and ordered the removal of the 15 MDO cases in conditional release from that program. Of the 156 MDO's, 76 or 49 percent were released to community parole supervision. The remaining 80 hospitalized cases were retained through various legal provisions for psychiatric treatment in institutions. Overall, parole supervision in the community for Gibson cases produced reasonably satisfactory results. Persons in need of psychiatric treatment were returned to custody when their condition warranted. Followup data on Gibson cases released to community parole supervision and on cases removed from conditional release are provided as well as data on violation charges or reasons for return to custody for Gibson cases released from March 1989 through March 1990. Appendixes contain California Senate Bill 1625 and a Department of Corrections administrative bulletin concerning the Mentally Disordered Offender Act. 5 tables