State v. Sarinske
In State v. Sarinske, 91 Wis. 2d 14, 49-50, 280 N.W.2d 725 (1979), Roger Sarinske shot and killed his wife's lover after finding her with him.
At trial, the two medical experts presented by the defense testified that Sarinske lacked mental capacity to appreciate the wrongfulness of his actions or to conform his conduct to the requirements of the law. See id. at 48.
However, the state's medical expert testified that Sarinske was not suffering from mental disease or defect. See id.
The supreme court upheld the jury's conclusion that Sarinske did not carry his burden of showing that he lacked capacity to be held responsible. See id. at 49.
The court explained that the jury was free to disbelieve the defense experts entirely, "and even if the state declines to present any experts in rebuttal, the accused may fail to satisfy his or her burden of affirmatively proving that he or she was suffering from mental disease." Sarinske, 91 Wis. 2d at 48-49. The court stated that the defense experts substantially relied on information provided by Sarinske, and that the jury could question their opinions on that ground alone. See id. at 49.
Finally, the court pointed out that Sarinske had no history of mental illness and one expert testified that Sarinske did not have a mental disease or defect. See id.