{ "id": "2026-04-04-university-of-wisconsin-madison-influenza-research-institute-poisoning", "slug": "university-of-wisconsin-madison-influenza-research-institute-poisoning-2026-04-04", "institution": { "name": "University of Wisconsin-Madison", "shortName": "UW-Madison", "state": "WI", "type": "public-r1", "alertSystemName": "WiscAlerts", "enrollment": 49000 }, "incident": { "date": "2026-04-04", "type": "workplace-violence", "cleryCategory": "advisory", "headline": "A Foul-Tasting Sip: A UW-Madison Lab Scientist Allegedly Poisons a Promoted Coworker's Water Bottle", "summary": "A coworker at UW-Madison's [Influenza Research Institute noticed a foul taste and strange odor](https://www.wpr.org/education/higher-education/uw-madison-employee-kuroda-felony-charges-poison-coworker) coming from his water bottle on April 4, 2026, and later from his shoes; testing found chloroform levels 'so high the test strips were not able to provide an accurate value.' UW-Madison police [arrested staff scientist Makoto Kuroda, 41](https://badgerherald.com/news/campus/2026/04/21/uw-veterinary-medicine-lab-employee-arrested-charged-after-attempting-to-poison-coworker/), who allegedly admitted 'I did it' and told investigators he had been upset since the coworker was promoted over him.", "resolution": "confirmed-threat", "outcome": "The coworker, identified in charging documents only as TM, spit out the contaminated water and was not seriously injured. Makoto Kuroda was arrested on April 10, 2026, and charged by the Dane County District Attorney with second-degree recklessly endangering safety and tampering with a household product with intent to injure. UW-Madison stated the incident was unrelated to the Institute's research activities and involved only routine laboratory supply chemicals.", "casualties": { "killed": 0, "injured": 0 } }, "alerts": [ { "sequence": 1, "type": "follow-up", "timestampApprox": "Mid-April 2026, following Makoto Kuroda's April 10, 2026 arrest", "channel": "website", "verbatimText": "The incident at IRI was unrelated to the research that takes place there, and there is no evidence it involved any research materials other than the routine laboratory supply chemicals. The incident was reported by staff members to laboratory leadership who promptly reported it to the University of Wisconsin-Madison Police Department.", "isVerbatimConfirmed": true, "sourceUrl": "https://news.wisc.edu/information-about-research-employee-arrest/", "sourceDescription": "UW-Madison News official statement, \"Information about research employee arrest\"", "annotations": [ "This was a written UW-Madison News statement, not a live WiscAlerts emergency text: the poisoning was discovered internally by lab staff, reported to laboratory leadership, and investigated over several days before an arrest, rather than unfolding as an active, in-progress threat requiring immediate campus-wide notification", "The statement's emphasis that the incident was 'unrelated to the research that takes place there' was a deliberate reassurance given the Influenza Research Institute's high-containment, Federal Select Agent Program-regulated status, distinguishing a personal workplace grievance from any biosecurity concern", "UW-Madison confirmed all IRI employees, including Kuroda, undergo an FBI security risk assessment as a condition of working at the facility, underscoring how a vetted, credentialed employee was still the source of the threat" ], "characterCount": 336 } ], "context": "A staff scientist at UW-Madison's Influenza Research Institute (IRI), later identified only as TM in charging documents, took a sip from his water bottle on April 4, 2026, noticed an unfamiliar, foul taste, and spit it out; on April 6 he noticed a strange odor coming from his shoes. He reported both incidents to laboratory leadership, who [reported it to the University of Wisconsin-Madison Police Department](https://news.wisc.edu/information-about-research-employee-arrest/). Testing found the water bottle contained chloroform at levels [\"so high the test strips were not able to provide an accurate value,\"](https://www.nbcnews.com/news/us-news/university-wisconsin-scientist-allegedly-tired-kill-lab-colleague-pois-rcna341216) according to the criminal complaint, which noted that because chloroform dissipates over time, the high reading meant the original exposure was significant. Investigators say [Makoto Kuroda, 41, allegedly told them 'I did it'](https://www.wmtv15news.com/2026/04/15/i-did-it-uw-madison-lab-worker-allegedly-admitted-trying-poison-coworker/) when confronted, and that he had placed small amounts of paraformaldehyde mixed with Trizol, both common laboratory chemicals, into the coworker's water bottle and shoes. Kuroda told investigators he had been upset with the coworker for some time, particularly after the coworker was promoted and he was not, and that he felt the coworker had begun treating subordinates poorly. UW-Madison Police arrested Kuroda on April 10, 2026; the Dane County District Attorney charged him with second-degree recklessly endangering safety and tampering with a household product with intent to injure.", "keyFindings": [ "The motive investigators cited, resentment after a coworker's promotion, places this squarely in workplace violence rather than any dispute connected to the Institute's influenza research itself, a distinction UW-Madison's public statement went out of its way to draw", "Because the poisoning was discovered and investigated internally before an arrest, UW-Madison's public communication was a written statement issued after the fact rather than a live WiscAlerts emergency notification", "The chloroform concentration detected was high enough that testing equipment could not quantify it precisely, and investigators noted the chemical's tendency to dissipate meant the true initial exposure was likely even higher", "All Influenza Research Institute employees, including the accused, are subject to an FBI security risk assessment under the Federal Select Agent Program, illustrating that even highly vetted, credentialed lab staff can pose a workplace-violence risk to colleagues" ], "sources": [ { "title": "UW-Madison employee faces felony charges for allegedly trying to poison coworker (Wisconsin Public Radio)", "url": "https://www.wpr.org/education/higher-education/uw-madison-employee-kuroda-felony-charges-poison-coworker", "type": "local-media" }, { "title": "University of Wisconsin scientist accused of trying to poison lab colleague who got promotion (NBC News)", "url": "https://www.nbcnews.com/news/us-news/university-wisconsin-scientist-allegedly-tired-kill-lab-colleague-pois-rcna341216", "type": "local-media" }, { "title": "'I did it': UW-Madison lab worker allegedly admitted to trying to poison coworker (WMTV NBC15)", "url": "https://www.wmtv15news.com/2026/04/15/i-did-it-uw-madison-lab-worker-allegedly-admitted-trying-poison-coworker/", "type": "local-media" }, { "title": "UW Veterinary Medicine lab employee arrested, charged after attempting to poison coworker (The Badger Herald)", "url": "https://badgerherald.com/news/campus/2026/04/21/uw-veterinary-medicine-lab-employee-arrested-charged-after-attempting-to-poison-coworker/", "type": "student-newspaper" }, { "title": "Information about research employee arrest (UW-Madison News, official statement)", "url": "https://news.wisc.edu/information-about-research-employee-arrest/", "type": "official-archive" }, { "title": "UW lab researcher admits to adding poisonous chemicals to coworker's water bottle, shoes (The Daily Cardinal)", "url": "https://www.dailycardinal.com/article/2026/04/uw-lab-researcher-admits-to-adding-poisonous-chemicals-to-coworkers-water-bottle-shoes", "type": "student-newspaper" } ], "confidence": "high", "tags": [ "workplace-violence", "laboratory", "poisoning", "wisconsin", "madison", "influenza-research-institute", "biosecurity", "no-injuries" ], "dateAdded": "2026-07-03", "lastUpdated": "2026-07-03", "addedBy": "ingestion" }