More than four decades after a man died from cyanide poisoning inside an Idaho church, investigators have identified him—and uncovered clues that may link his story to the notorious Tylenol murders.
For years, he was known only as the “unknown wanderer.” The man was found dead at Boise’s Sacred Heart Catholic Church on Dec. 4, 1982, according to a press conference held by the Ada County Sheriff’s Office.
Authorities now say the man was Dr. Mathew Francis Betkouski, an organic chemist from a prominent Los Angeles family who had experienced lifelong struggles with mental illness.
Investigators stopped short of naming Betkouski as a suspect in the 1982 Tylenol murders, which killed seven people in the Chicago area. Still, they pointed to several unsettling details that could connect the two long-unsolved cases.
“There’s still a lot of questions we don’t have answers to,” Sheriff Matt Clifford said. “And that’s part of why we’re standing here today.”
Who Was Idaho’s Unknown Wanderer?
The Idaho mystery began on Dec. 4, 1982, when an unidentified man entered Sacred Heart Catholic Church in Boise. By the end of the day, he had died from cyanide poisoning, according to the medical examiner.
“He had nothing on him that told us who he was, and he was carrying a wallet, no cards in it, but you could still see the sweat lines where the cards used to be,” Clifford said during the press conference. “He had an ink marker, a lighter, a Seiko wristwatch, a leather belt with a distinctive coin centerpiece and a bolo tie made of turquoise and silver.”
Investigators also found an envelope containing 19 $100 bills, two key rings holding nearly 30 keys and a typed note signed by William L. Toomey. That name, however, proved to be an alias.
“The coroner noted some other things that stuck with the investigators for decades,” Clifford said. “The man’s fingernails were finely filed. His hair had been dyed and styled, possibly with a razor. His pants looked like they had never been worn, or just or had just been pressed.”
His pronounced tan suggested he had recently lived in a warmer climate. Investigators also determined that he did not appear to have been living on the streets.
Authorities eventually gave him the name “unknown wanderer.”
Idaho’s Unknown Wanderer Identified as Dr. Mathew Francis Betkouski
The case gained national attention when it was featured on Unsolved Mysteries in 1990, but it remained unresolved for decades.
The investigation took a new turn after Ada County Sheriff’s Detective Tim Cooper was approached by a parishioner who wanted to know whether anything had happened in the case.
“I was drinking cheap gas station coffee in a parking lot, and I was approached by a member of the Sacred Heart Church, and they expressed an interest in the case and wondered what was going on with it,” Cooper said at the press conference. “So we started looking into it.”
Cooper began by reexamining the keys found among the man’s belongings. One bore a marking indicating it had come from a hardware store in Jacksonville, Florida. Another etching, which investigators had previously misread, pointed them to a Jacksonville street called Mills Court, he said.
Working with Jacksonville investigators and records officials, Cooper searched property deeds from the late 1970s and early 1980s. The effort led them to a man whose death had been recorded in 1989. Investigators contacted his only surviving family member, a brother in Los Angeles, and learned that the man had vanished in 1982 but was not officially declared dead in absentia until 1989.
Cooper said investigators obtained a DNA sample from the brother and determined that the two men shared the same biological father. That evidence ultimately identified the unknown wanderer as Betkouski.
Authorities Question If Dr. Mathew Francis Betkouski Could Be Linked to the Tylenol Murders
As investigators reconstructed Betkouski’s life, they found a history marked by serious personal difficulties.
“He was a Ph.D. holder, and by all accounts, he was a brilliant man,” Cooper said. “But he struggled to connect with people in life.”
Cooper said Betkouski had shown a strong interest in chemistry and explosives from an early age. After suffering a traumatic brain injury in 1974, those struggles reportedly became even more severe.
While working for a flavors and fragrances company in Jacksonville, coworkers, according to Cooper, reported that Betkouski was sometimes seen talking to himself and had discussed carrying out the perfect crime, using cyanide as a “less messy” murder weapon.
Those who knew him tried to get him help and he spent two and a half months in a psychiatric facility in Los Angeles in 1978, according to the press conference. When he returned to work in Florida, Cooper said his “situation had not improved” and he was fired.
MORE STORY: Herbert Wigwe's Parents: Exploring His Ethnic Background and Family Information – NewsFinale
In writings investigators recovered, Betkouski talked about “the possibility of trying to manage schizophrenia and depression” and “the possibility to experience feelings of euphoria brought on by imaginary thoughts of violence,” Cooper said.
After losing his mother in 1979, Betkouski continued to receive psychiatric treatment in Florida until landing a job with Lockheed at a NASA-related project at the White Sands Test Facility in New Mexico. He worked there until 1982.
According to Cooper, one of Betkouski’s fellow scientists recalled that he “made a comment about how poison could be introduced into over-the-counter capsules if a person wished to do so.”
He was fired from his job after an alleged incident at a local pharmacy where he tried to obtain some type of pills or capsules for an experiment.
“Dr. Betkouski created a disturbance at the location, and the police were summoned,” Cooper explained at the press conference. “It should be noted that Dr. Betkouski was conducting experiments in his home garden at the time. It’s unknown if these experiments would have required the use of pills or capsules.”
After Betkouski’s brother passed away in 2021, other family members permitted investigators to search his childhood bedroom in Los Angeles, where he was known to stay as an adult. They discovered a map of Chicago, made in the 1970s, and a small bottle of cyanide with a handwritten label.
The bottle contained sodium cyanide, although the Tylenol murders used potassium cyanide. Cooper said after the bottle was tested they discovered it contained organic properties including peach pits and apricot seeds and was likely homemade.
They also found photos they believe were taken in 1981 of Betkouski in Chicago.
Cooper said investigators also uncovered an unsolved cyanide poisoning case in Las Cruces, New Mexico from 1982—although Betkouski was not named as a suspect in that death.
What Were the Tylenol Murders?
Authorities in Idaho are now wondering whether Betkouski could have been involved in unsolved cyanide murders in Chicago the same year of his death.
Fear spread through Chicago in 1982 after seven people died from purchasing Tylenol at drug stores containing cyanide-laced capsules.
Mary Kellerman, 12, died in Elk Grove Village after taking two capsules for a cold on Sept. 29, 1982, CBS News reported.
Arlington Heights postal worker Adam Janus, 27, died the same day from taking cyanide laced pills from a Tylenol bottle. His brother Stanley, 25, and sister-in-law Theresa also died after they inadvertently took pills from the same bottle, per the outlet.
Over the next few days, Mary Reiner, 27, Mary McFarland, 31, and Paul Jean Prince also lost their lives.
The killings shocked the community and Johnson & Johnson ordered Tylenol to be taken off the shelves across the country.
The murders have never been solved.
Authorities were unable to place Betkouski in Chicago in September of 1982 and said they could not name him as a suspect in the killings.
FBI Responds to Possible Tylenol Murders Development
Authorities added that they’d passed all the information they’d gathered on Betkouski to Chicago investigators.
“There have been repeated claims over the past 44 years about alleged links to the Tylenol Murders which have remain unsubstantiated,” the FBI Chicago said in a statement to Oxygen. “Out of respect for the ongoing, legitimate investigation, those impacted by the tragedy, and the law enforcement partners who have provided genuine support since the start, the FBI remains the lead on investigating and releasing credible information to the public once the evidence yields a true case resolution.”
A spokesperson for the Arlington Heights Police Department also told the outlet it had received the information from Idaho investigators and was still working to determine “the individual or individuals responsible for the 1982 Tylenol murders.” Oxygen also reached out to the department, but did not receive an immediate reply.
Idaho authorities are asking for anyone with information about Betkouski or his activities before his death to come forward.