(concurring). I agree with the majority that this case should be remanded to the circuit court.
The state asks the court to uphold the constitutionality of sec. 971.17, Stats., (1987-88). According to the state, under sec. 971.17 a defendant found not guilty by reason of mental illness, who later does not suffer from mental illness, may be confined in a mental institution upon the state's proof by clear and convincing evidence that the acquittee is dangerous; the confinement may continue for the maximum period to which the acquit-tee could have been sentenced under the criminal law. The defendant argues that confining an acquittee in a mental institution solely upon proof of dangerousness alone is unconstitutional.
The majority opinion accepts neither the state's nor the defendant's position about sec. 971.17. Instead the majority opinion concludes that either "mental illness or behavioral disabilities which render the *842acquittee dangerous" must exist before confinement can be continued.1 Majority op. at 837. The majority concludes that a mental illness or behavioral disability must exist to provide "medical justification" for continuing the confinement of a dangerous acquittee under sec. 971.17, majority op. at 837, and further that the circuit court must find that the committing facility can provide treatment appropriate to the acquittee's needs.2 Majority op. at 837, 841.
Section 971.17, Stats., (1987-88), is silent about the relationship of mental illness, behavioral disability, medical justification, or treatment to the continued confinement of an acquittee based on dangerousness. The majority opinion appears to graft these requirements onto sec. 971.17, because it concludes that such an interpretation of the statute is needed to render it constitutional. The majority is appropriately heeding a teaching of Foucha: "Due process requires that the nature of commitment bear some reasonable relation to the purpose for which the individual is committed." Foucha v. Louisiana, 112 S. Ct. 1780, 1785 (1992).
I cannot join the majority opinion, however, because I conclude that the majority's interpretation of *843sec. 971.17 violates another teaching of Foucha. As the state's brief explains, Foucha rejected the notion that the state could confine an acquittee in a mental institution on the basis of a condition which is not a mental illness, would not have justified the insanity commitment and was not the basis of that commitment at trial. 3 Thus a "behavioral disorder" (an important concept in the majority opinion but undefined) that renders the acquittee dangerous may be analogous to the antisocial personality condition in Foucha, which did not rise to the level of a mental illness or defect on which an insanity commitment could be based.
I recognize that Foucha is a troublesome decision and the subject of conflicting interpretations by courts and commentators. The majority struggles to avoid the conclusion mandated by Foucha, that mental illness as well as dangerousness are necessary grounds to continue confinement. If I read the majority opinion correctly, the state can continue to confine an acquittee who is not mentally ill but is behaviorally disordered and dangerous if the state can treat the acquittee, but the state must release an acquittee who is not mentally *844ill but is dangerous if no treatment is available at the institution.4
I am unable to determine from the majority opinion what the circuit court should do on remand. I conclude that on remand the circuit court should determine whether Randall is mentally ill or dangerous or both.
For the reasons set forth, I concur in the mandate.
The phrases "behavioral disorder" and "behavioral disability" are not used in either the civil or criminal commitment statutes. The majority apparently considers that dangerousness is caused by an underlying behavioral disability or disorder, but the majority gives no basis for this reasoning.
The majority further concludes that Wisconsin's mental health facilities are designed to treat "mental and behavioral disorders" that can render an acquittee dangerous. Majority op. at 833-834,837. The majority cites no authority suggesting that a behavioral disorder is treatable or that the "treatments" listed by the majority do in fact address behavioral disorders. The parties did not brief these issues.
The State's brief reads as follows:
The Court in Foucha also rejected the notion that the state could confine Foucha in a mental institution on the basis of a newly diagnosed condition (antisocial personality), which the state conceded is not a mental illness and which apparently could not have justified the insanity commitment and was not the basis of that commitment in the first place simply because the condition had been evidenced by conduct in the mental institution which demonstrated Foucha may be dangerous to himself or others. Foucha, 112 S. Ct. at 1784-85. The state in the instant case, of course, has never suggested such an argument.
State's brief at 22.
"To be constitutionally permissible, the continued confinement of a sane but dangerous insanity acquittee in a mental health facility, must have some therapeutic value." Majority op. at 817.