Scientist accused of poisoning co-worker’s water bottle after being denied promotion, authorities say

MADISON, Wis. (WMTV/Gray News) - A scientist at a university is accused of trying to poison his co‑worker, authorities said.

According to a criminal complaint, a person who works at the Influenza Research Institute at the University of Wisconsin‑Madison noticed an odd smell coming from his water bottle on April 4 and said it tasted strange.

He also reported an odd smell coming from his shoes and a grocery bag, and told another employee, who then called police.

A lab test of the water bottle revealed a high level of chloroform.

A staff member at the lab called police after 41‑year‑old Makoto Kuroda allegedly told the victim, “I did it.”

He also admitted to putting a chemical called paraformaldehyde in the victim’s drink. Paraformaldehyde is very toxic at low levels.

When asked why he placed the chemical in the victim’s drink, Kuroda allegedly said he was upset that the victim was not following lab rules, not wearing a lab coat and goggles and that multiple small grievances had built up over time.

Kuroda also allegedly became upset when the employee was promoted and Kuroda was not.

Kuroda is accused of second-degree recklessly endangering safety and tampering with household products. He is set for a preliminary hearing on April 21.

The university confirmed in a statement that an investigation is underway and that Kuroda is on administrative leave.