State v. Koput
In State v. Koput, 142 Wis. 2d 370, 395, 418 N.W.2d 804 (1988), the supreme court held that a unanimous jury verdict was not required on the issue of a defendant's mental responsibility. 142 Wis. 2d at 374.
However the court did not clearly establish that the responsibility phase is sufficiently removed from the overall criminal proceedings such that 972.02(1) should not apply.
The court explained that the phases of a bifurcated trial serve different purposes, as the first phase settles the issue of criminal guilt while the responsibility phase is dispositional in nature. See Koput, 142 Wis. 2d at 388-89.
However the court also stated:
"Clearly, at one time when the burden of proving sanity was on the state and a unanimous finding of sanity was required, the "proceeding" was criminal. Hence, to some degree, in its ancestry at least, it is not completely divorced jurisgenetically from its antecedents. We, therefore, will not denominate it a civil proceeding. Rather, it is a special proceeding in the dispositional phase of a criminal proceeding-a proceeding that is not criminal in its attributes or purposes." Id. at 397.