[REVISION HISTORY]

Identification of potential Tylenol murder suspect

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2026-09-23 19:32 UTC → 2026-09-24 04:13 UTC · added ~~removed~~

Investigators have identified Dr. Mathew Francis Betkouski, an organic chemist known as the ‘unknown wanderer,’ as a potential suspect in the 1982 Tylenol murders in Chicago. Betkouski was found dead in a Boise, Idaho, church in December 1982 after consuming cyanide. While police noted that homemade cyanide found among his belongings differed from the poison used in the Chicago killings, investigators discovered maps of Chicago and photos of Betkouski in the city among his possessions. Following a breakthrough in the cold case, the Ada County Sheriff’s Office confirmed Betkouski’s identity through DNA comparison after tracing property records linked to a key found with his body. Betkouski had died by suicide in 1982, leaving behind a note using the alias ‘Wm. L. Toomey.’ Authorities are now sharing these findings with Chicago-area officials to determine if he was responsible for the cyanide-laced capsules that caused at least seven deaths. New details indicate Betkouski had a history of mental health treatments and worked in a lab where he allegedly took chemicals. Forensic psychiatrist Dr. Park Dietz stated that both forensic psychiatrists and an FBI group considered Betkouski a viable suspect. While investigators note they lack a ‘smoking gun’ to definitively name him as the killer, they have highlighted links including his professional background in chemistry, his history of volatility, and reported comments he made regarding the introduction of poison into medication capsules. The Chicago Police Department is currently collaborating with Idaho authorities to investigate these connections.

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