Tylenol Murders Twist as Dead Chemist’s Secret Chicago Links Emerge After 44 Years

The 44-year-old mystery surrounding Idaho’s “Unknown Wanderer” has been solved, but the man’s past has opened a new line of inquiry into the still-unsolved 1982 Chicago Tylenol murders.

Ada County investigators identified the unidentified man Wednesday, Sept. 23, as Dr. Mathew Francis Betkouski, an organic chemist who died from cyanide poisoning inside Boise’s Sacred Heart Catholic Church on Dec. 4, 1982.

Investigators said evidence recovered from his family’s belongings included a Chicago map, photographs taken in the Chicago area and a bottle containing homemade sodium cyanide. Authorities stressed they cannot place Betkouski in Chicago during the week of the Tylenol killings and are not naming him as a suspect.

Who Was Mathew Francis Betkouski?

Betkouski had worked in chemistry-related jobs, including at Lockheed’s White Sands Test Facility in New Mexico. According to investigators, he had a documented interest in chemistry, explosives and poisons.

Detective Tim Cooper said coworkers had recalled Betkouski discussing the use of poison in a “perfect crime.” Investigators also said he was fired from Lockheed in March 1982 following an incident at a pharmacy involving pills or capsules he allegedly wanted for an experiment.

Betkouski eventually ended up in Boise, where he died by ingesting cyanide. At the time, he was carrying nearly 30 keys, $1,900 and a typed suicide note signed with the name “William L. Toomey.” His identity remained unknown for decades.

How Investigators Finally Identified the “Unknown Wanderer”

The identification breakthrough centered on one of the keys found among Betkouski’s belongings.

Cooper determined that a marking on the key pointed to a hardware store in Jacksonville, Florida. Property records led investigators to a home associated with a man who had disappeared in 1982. His surviving brother, living in Los Angeles, provided a DNA sample.

Investigators compared that DNA with material from the unidentified man’s wallet and determined that the two men shared the same father. The “Unknown Wanderer” was finally identified as Betkouski.

The Ada County Sheriff’s Office became involved in the case in 2018, and the investigation was formally reopened in 2019. Investigators also searched more than 17,000 missing-person records, although Betkouski had never been reported missing.

What Does He Have To Do With the Tylenol Murders?

The potential Chicago connection emerged from items recovered from Betkouski’s family’s possession in 2021.

Investigators found a hand-drawn map of Chicago, photographs of Betkouski in the Chicago area and a small bottle containing sodium cyanide. The photos were initially believed to have been taken in 1982 but were later dated to around December 1981. Investigators have not established that Betkouski returned to Chicago in September 1982.

The cyanide found among Betkouski’s belongings was sodium cyanide, while the poison used in the Tylenol killings was potassium cyanide. Investigators believe the material found with Betkouski may have been homemade from peach and apricot pits.

Forensic psychiatrist Dr. Park Dietz, who has worked on the Tylenol case, said he presented the Betkouski information to other forensic psychiatrists and an FBI group, which he said considered Betkouski a viable suspect.

The 1982 Tylenol Murders Remain Unsolved

The Chicago-area killings began on Sept. 29, 1982, when 12-year-old Mary Kellerman died after taking cyanide-laced Extra-Strength Tylenol. Six other people subsequently died after ingesting poisoned capsules, bringing the death toll to seven.

The poisonings triggered a nationwide Tylenol recall and helped lead to major changes in tamper-resistant packaging for over-the-counter medication.

James Lewis, the man long regarded as the primary suspect, was convicted of extortion after a letter demanding money was sent to Johnson & Johnson in connection with the killings. He was never convicted of the murders and died in 2023.

The FBI said Wednesday that claims of connections to the Tylenol killings have repeatedly remained unsubstantiated. “The FBI remains the lead on investigating and releasing credible information to the public once the evidence yields a true case resolution,” the agency said.

Chicago police also confirmed they are reviewing the Idaho information, saying the Tylenol investigation “remains an open cold case.” Arlington Heights police said they had received and reviewed the material and would continue working with other agencies.