University of Wisconsin-Madison Researcher Charged with Poisoning Coworker

Makoto Kuroda, a 41-year-old staff scientist at the Influenza Research Institute within the University of Wisconsin-Madison's School of Veterinary Medicine, faces felony charges for allegedly poisoning a coworker. The charges, filed on April 14, 2026, include recklessly endangering safety and tampering with a household product with the intent to kill, injure, or endanger someone's health. The incident reportedly stemmed from Kuroda's resentment towards the victim, identified only by the initials T.M., who had recently received a promotion.

UW-Madison employee faces felony charges for allegedly trying to poison coworker

The poisoning incident occurred on April 2, 2026, when T.M. opened a new water bottle from Trader Joe’s, drank from it, and left it on his desk. Upon returning on April 4, he noticed a foul odor and a chemical taste, leading him to report the matter to the University of Wisconsin Police Department (UWPD). Testing revealed high levels of chloroform in the water, a toxic chemical commonly used in laboratories.

UW lab researcher admits to adding poisonous chemicals to coworker's water bottle, shoes

Kuroda allegedly admitted to the poisoning both verbally to T.M. and in an email to a supervisor, stating, “I did it. I have also informed the person himself. I am very sorry.” He reportedly expressed that his actions were motivated by feelings of disrespect and frustration over T.M.'s promotion and perceived disregard for lab rules.

UW-Madison employee faces felony charges for allegedly trying to poison coworker

Kuroda is accused of adding a mixture of Paraformaldehyde and Trizol, both hazardous chemicals, to T.M.'s water and shoes. The complaint indicates that Kuroda used approximately 0.5 microliters of Paraformaldehyde in the water bottle and about 1.5 microliters in each shoe. Chloroform exposure can lead to severe health issues, including liver and kidney damage, with potentially fatal outcomes at high doses.

UW-Madison employee faces felony charges for allegedly trying to poison coworker

Following the incident, the University of Wisconsin-Madison placed Kuroda on administrative leave and revoked his research privileges. University spokesman John Lucas confirmed that an investigation is underway, although further details are limited due to privacy laws and ongoing criminal proceedings.

UW-Madison employee faces felony charges for allegedly trying to poison coworker

The case has raised concerns about workplace safety and mental health within academic environments. Critics argue that the incident reflects a troubling culture of competition and resentment in research settings, emphasizing the need for better support systems for employees facing workplace stressors.

UW-Madison employee faces felony charges for allegedly trying to poison coworker

Kuroda is scheduled for a preliminary hearing on April 21, 2026, at the Dane County Courthouse. As the investigation continues, the university is expected to review its policies regarding employee conduct and safety in laboratory environments.

UW-Madison employee faces felony charges for allegedly trying to poison coworker

• “I did it.” — Makoto Kuroda, Staff Scientist

New York Times

• “The high value was concerning because Chloroform dissipates over time and a high sample now means the initial exposure was also significant,” — Criminal Complaint

UW-Madison employee faces felony charges for allegedly trying to poison coworker

This incident underscores the serious implications of interpersonal conflicts in professional settings, particularly in high-stakes environments like scientific research.

New York Times