Issue/Holding: A trial court has inherent and statutory authority (§ 906.11) to order that a defendant provide a pretrial summary of the specific “McMorris” evidence (violent acts of the alleged victim the defendant knew about, as relevant to self-defense) he or she wants to introduce at trial:
¶26 Given the limited nature of the evidence covered in this order——that is, the requirement that McClaren give notice of the specific McMorris evidence he wants to introduce and which he was aware of on the night of the incident——this order fits comfortably into Wis. Stat. § 906.11’s description of the court’s sphere of control. The court is, in fact, required to “exercise reasonable control” over the “present[ation of] evidence” so that it can be done effectively and with minimal wasted time. See State v. Wallerman, 203 Wis. 2d 158, 168, 552 N.W.2d 128 (Ct. App. 1996). Both concerns were specifically mentioned by the circuit court with regard to this order. This is precisely the type of admissibility of evidence questions that circuit courts should be attempting to resolve in advance of trial.  …
¶28 Under the circumstances presented here, where McClaren seeks to introduce McMorris evidence in support of a self-defense claim, the circuit court has the authority under Wis. Stat. § 906.11, in conjunction with Wis. Stat. § 901.04(3)(d), to order the defendant to disclose prior to trial any specific acts that he knew about at the time of the incident and that he intends to offer as evidence so that admissibility determinations can be made prior to trial.
The disclosure order is constitutional: the court analogizes to alibi-disclosure, Williams v. Florida, 399 U.S. 78 (1970), ¶35, while stressing that the trial court’s order “absolutely required” reciprocal prosecutorial disclosure, ¶¶38-39. As for enforcement of the order, guidance is taken from Taylor v. Illinois, 484 U.S. 400 (1988):
¶43 We agree with the State. The United States Supreme Court has established a test for excluding evidence and has said that under certain circumstances, exclusion of evidence does not violate a defendant’s constitutional rights. There are sanctions short of excluding evidence, of course. The Court cited a case, for example, that “[gave] consideration to the effectiveness of less severe sanctions, the impact of preclusion on the evidence at trial and the outcome of the case, the extent of prosecutorial surprise or prejudice, and whether the violation was willful.” Taylor, 484 U.S. at 415 n.19 (citing Fendler v. Goldsmith, 728 F.2d 1181 (9th Cir. 1983)). However, as Taylor makes clear, even the sanction of excluding evidence against a defendant is constitutionally permissible in certain cases, such as where there have been willful violations “motivated by a desire to obtain a tactical advantage.” Taylor, 484 U.S. at 415.¶44 As we noted above, Taylor states well the balancing of interests that goes into a court’s oversight of a trial:
It is elementary, of course, that a trial court may not ignore the fundamental character of the defendant’s right to offer the testimony of witnesses in his favor. But the mere invocation of that right cannot automatically and invariably outweigh countervailing public interests. The integrity of the adversary process, which depends both on the presentation of reliable evidence and the rejection of unreliable evidence, the interest in the fair and efficient administration of justice, and the potential prejudice to the truth-determining function of the trial process must also weigh in the balance.
Id. at 414-15 (emphasis added).¶45 Whether a violation merits the extreme sanction of exclusion must be determined by a circuit court after a violation has occurred, and under the parameters set forth by the United States Supreme Court in Taylor.
¶50 … It appears from the record that the circuit court intended to exclude from trial any evidence that McClaren attempted to offer at trial in violation of the order; we clarify here that while such a sanction may be permitted, lesser sanctions must be considered first, and that the extreme sanction of exclusion is permissible only after the circuit court has determined that the violation was “willful and motivated by a desire to obtain a tactical advantage that would minimize the effectiveness of cross-examination and the ability to adduce rebuttal evidence,” the test set forth in Taylor.
Potentially vast as the implications might be, it is probably wise to treat the holding as narrow, a mere matter of the timing of something that would have to be disclosed sooner or later anyway.