The petitioner in this case argued that the psychiatric determination of sexual dangerousness arose from information he gave to court-ordered psychiatrists in violation of the Fifth Amendment privilege against self-incrimination. The petitioner tried unsuccessfully to persuade the Court that the commitment proceedings under the Illinois Sexually Dangerous Persons Act were criminal in nature and that the lack of Miranda warnings made his statements to psychiatrists inadmissible. However, the Court presumed that all involuntary commitments of the mentally ill were civil proceedings because they were designed to provide treatment. Thus, it held that the Fifth Amendment privilege was inapplicable. However, it failed to recognize that the commitment scheme at issue made distinctions between classes of mentally ill persons. The Court's analysis also failed to include the post-commitment conditions of confinement and the right to treatment in the least restrictive setting. 138 footnotes.