The circuit court did not err by requiring Herling to prove by clear and convincing evidence that he had amnesia that prevented him from mounting an adequate defense.
A defendant may be denied a fair trial if he has amnesia that deprived him of the ability to mount a defense by, e.g., affecting his ability to consult with or assist counsel or to take the stand and offer his own description of the events. State v. McIntosh, 137 Wis. 2d 339, 347-50, 404 N.W.2d 557 (Ct. App. 1987). But the defendant must first establish he in fact suffers from amnesia. Herling argues that the appropriate burden of proof for establishing his amnesia is the “preponderance of the evidence” standard, and that if the circuit court had applied this lower standard rather than the “clear and convincing evidence” standard it likely would have found that Herling had amnesia and that his amnesia deprived him of a fair trial. The circuit court applied the right standard:
¶8 Herling’s argument erroneously assumes that there is no Wisconsin case law deciding the proper burden of proof for establishing amnesia…. In a case identified by the circuit court, Muench v. State, the defendant claimed, as Herling does here, that “he was deprived of his constitutional rights to a fair trial and effective assistance of counsel while being tried when suffering from amnesia.” 60 Wis. 2d 386, 392, 210 N.W.2d 716 (1973) (overruled on other grounds by Schimmel v. State, 84 Wis. 2d 287, 267 N.W.2d 271 (1978)). Noting that “[t]he claim of amnesia is one easily fabricated after the event by one seeking to avoid responsibility for his acts,” our supreme court held that “[f]or this reason alone [amnesia] is an affirmative defense that must be established by the defendant by a clear preponderance of the credible evidence.” Muench, 60 Wis. 2d at 392-93. As noted above [(¶1 n.1)], the parties in this case agree that “clear preponderance” means the higher burden “clear and convincing.”
Herling’s alternative argument—that imposing the “clear and convincing evidence” burden violates due process—is rejected as undeveloped. (¶9 n.5).