Two Criminal Cases Show How Courts Wrestle with Mania a Criminal Defense

When a manic episode leads to violence, the legal system faces a question it is poorly equipped to answer: Was the person responsible for what they did? Two recent criminal trials — one in Wisconsin, one in Ireland — illustrate how differently courts handle a bipolar disorder criminal defense, even when the psychiatric testimony tells a similar story.

Wisconsin: “He Was in a State of Mania”

In La Crosse, Wisconsin, Zachary Fritz stood trial for the homicide of his wife. His defense team argued that Fritz was experiencing a manic episode at the time of the killing and should be found not responsible.

“To achieve that degree of injury, that forceful of a series of injuries, and then still have the energy to run around and trash your home and stab the knife through the wall requires an incredible amount of energy, defense attorney Christopher Zachar argued during closing statements,” as reported by WEAU. Psychiatrist Dr. Dileep Borra testified in support of the defense.

The prosecution pushed back, arguing Fritz did not have bipolar disorder at all and that his behavior was caused by alcohol use. “When he’s sober… he has no problems with law enforcement, with work, with his family,” prosecutor Emily Rudd said. The bench trial concluded in March 2026 with the judge weighing the verdict. He was found not guilty.

Ireland: Jury Rejects Insanity Defense

In Kerry, Ireland, 55-year-old Billy Burns was convicted of murdering his 75-year-old mother, Miriam Burns, who was found strangled at her home in Killarney in August 2022. Burns pleaded not guilty by reason of insanity, arguing he was in a manic episode related to bipolar disorder when he killed her.

Two psychiatrists offered opposing conclusions, according to The Journal. Defense psychiatrist Dr. Eugene Morgan said Burns was hypomanic and met the criteria for insanity. Prosecution psychiatrist Dr. Stephen Monks agreed Burns was manic but said he still understood his actions were wrong and was able to refrain from them. The jury sided with the prosecution in just over six hours.

The case was complicated by Burns’ long history of violence toward his mother — dating back to his teenage years — and by his drug and alcohol use in the days before the killing. RTE reported that psychiatrists differed on whether substance use or mental illness was the primary driver.

The Bigger Picture

These cases highlight a tension at the heart of mental health law. A manic episode can impair judgment, fuel impulsivity, and distort reality — but courts must still determine whether the person knew right from wrong. The legal standard varies by jurisdiction: Wisconsin uses a “substantial capacity” test, while Ireland applies criteria under its Criminal Law (Insanity) Act.

For people living with bipolar disorder, these cases can feel deeply personal. The vast majority of people who experience mania are never violent. But when violence does occur during a manic episode, the courtroom becomes a place where psychiatric expertise, legal standards, and public fear collide — often with inconsistent results.

A note from Jayne Millerton: Cases like these are hard to write about because they feed the stigma that people with bipolar disorder are dangerous. Most of us are not. But pretending that mania never leads to harmful behavior doesn’t help anyone either. What I take from these cases is this: treatment matters. Staying on medication matters. And the legal system needs better tools to understand what a manic episode actually does to the brain.

For more information, visit NAMI’s bipolar disorder resource page or the Depression and Bipolar Support Alliance.

Sources: WEAU | The Journal | RTE

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