Betkouski lived in five states, never in Illinois or near Chicago
Ada County Sheriff’s Detective Tim Cooper reported Wednesday that cyanide found in the desk of Dr. Mathew Francis Betkouski was a different compound than the cyanide used in the 1982 cyanide-laced Tylenol poisonings that killed seven people in the Chicago area. Cooper, who reopened the cold case in 2019 and posthumously identified Betkouski as a possible suspect in the killings, said the substance in Betkouski’s desk appeared to be homemade.
The identification stemmed from an engraved key found with Betkouski’s body in a Boise church. That key led investigators to a street in Jacksonville, Florida, where a property owner had disappeared in 1982, Cooper said. Detectives used photographs and DNA testing to confirm Betkouski’s identity. Betkouski fatally poisoned himself with cyanide inside the church more than 40 years ago and was buried anonymously.
Once detectives identified Betkouski and began researching his background, former colleagues and acquaintances told investigators that he had worked in drugstores, had a history of volatility, was fascinated by the idea of a “perfect crime,” and once said cyanide was a means to kill without detection, Cooper said.
Detectives also found cyanide in Betkouski’s desk, which Cooper said appeared to be homemade and was a different compound than what was used in the 1982 killings. Betkouski lived in five states throughout his life but never in Illinois or close to Chicago, according to investigators. Photographs showed he visited the Chicago area a year before the killings, but it was not clear if he returned the following year.
The Chicago Police Department said in a statement Wednesday that its detectives have been in contact with Idaho authorities to determine whether the findings connect to the Tylenol murders investigation, which remains an open cold case. The department did not say whether it considers Betkouski a suspect.
For decades, investigators had pointed to James Lewis as the likely killer, though he was never charged. Lewis died in 2023 after serving more than 12 years in prison for sending an extortion note to Johnson & Johnson, the drug’s manufacturer at the time, demanding $1 million to “stop the killing.” When Lewis was arrested in 1982, he gave investigators a detailed account of how the killer might have operated, according to The Guardian. Lewis always denied involvement.
The 1982 poisonings killed seven people in the Chicago area who had taken Extra-Strength Tylenol capsules laced with cyanide. The case triggered a nationwide recall of the over-the-counter painkillers and, according to The Guardian, “ushered in child safety caps for medicines.” No one has ever been charged.