Invoking its discretionary reversal power, the court of appeals holds Vento is entitled to a new trial in the interests of justice on the issue of his mental responsibility under Wis. Stat. § 971.15 because the trial court applied the wrong legal standard and based its verdict on speculative testimony from an expert:
¶28 We agree with Vento that there is a substantial probability that a new trial would produce a different result because he met his burden under Wis. Stat. § 971.15(3). See [State v.] Murdock, [2000 WI App 170,] 238 Wis. 2d 301, ¶31. The evidence showing that Vento lacked substantial capacity either to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of the law was, as we will discuss more fully below, very strong, and certainly comprised “the greater weight of the credible evidence.” See Wis. Stat. § 971.15(3). But the trial court effectively required not only a showing that Vento lacked substantial capacity to appreciate the wrongfulness of his actions or to conform his behavior to the requirements of the law, but also a showing that there was no other possible explanation for his behavior. This is not the correct standard. See id. Had the trial court applied the correct standard in assessing the evidence, it is very likely that the court would have determined that Vento did in fact lack substantial capacity to appreciate the wrongfulness of his actions or to conform his behavior to the requirements of the law. Furthermore, the portions of testimony on which the trial court relied in making its determination, i.e., Dr. Collins’ testimony, were purely speculative. Dr. Collins’ theory that anger and aggression were “possible” causes of Vento’s conduct at the time of the attack was not supported by any evidence.
The court finds Vento’s case to be closely analogous to Murdock and State v. Kemp, 61 Wis. 2d 125, 211 N.W.2d 793 (1973), both cases that ordered a new trial in the interests of justice. Among the parallels between Vento and the defendants in those cases: Vento had a long history of mental illness and was not taking medication on the day of the incident; the expert testimony did not directly conflict, and the only expert who could not conclude Vento met the NGI standard admitted she lacked some of the relevant information; there was a lack of evidence of other explanations for Vento’s behavior; and the evidence that Vento at times appeared to be acting rationally did not mean he could not meet the NGI standard, and in fact only strengthened the conclusion he was acting on a delusion when he committed the battery. (¶¶29-35).
A very fact-dependent decision, as you’d expect, and a rare win under a demanding legal standard.