An Idaho sheriff’s office says a man who took his own life inside a Boise Catholic church in December 1982 may be tied to the Tylenol murders, the cyanide-laced capsule killings that left seven people dead in the Chicago area that fall.
A name for the Boise decedent—and a new lead
The Ada County Sheriff’s Office stated in a news release that the church decedent has been identified as Dr. Mathew Betkouski. When he was found in 1982, he carried no identification, only a large amount of cash and a typed letter bearing a false name, according to the sheriff’s office.
Cold case Detective Tim Cooper reopened the file in 2019 and determined through photos and DNA that a Florida man who disappeared in 1982 and the Boise decedent were the same person, the sheriff’s office said. Investigators also noted Betkouski had worked in two drugstores while in college and had discussed the use of cyanide to kill without detection—details that mirror the Tylenol case method in which cyanide was substituted for medicine in several capsules, killing seven people before the product was pulled from shelves.
Why the Tylenol case matters
As summarized by Chicago History and the source material, the 1982 Tylenol killings prompted nationwide recalls and new tamper-evident packaging rules. No suspect has been identified. One person who came forward was later dismissed as a fraud and jailed for attempting to extort money from Tylenol’s parent company.
What the detective and experts are saying
Forensic psychiatrist Dr. Park Dietz said that by 2021 he believed Cooper was making connections that linked Betkouski to the Tylenol case, according to the source material.
Cooper has publicly appealed for additional information about Betkouski’s movements. “Mathew Betkouski lived in five states over the course of his life — California, Texas, New Mexico, Ohio and Florida,” Cooper said. “We’re hoping that getting his story out generates new leads, not just for this case, but for others we may not even know about yet. I’m especially interested in learning more about his movements between Oct. 15 and Dec. 4, 1982.”
Cooper further described Betkouski’s background: “Dr. Betkouski had a documented fascination with chemistry and the use of explosives from a young age, and did put others at risk on more than one occasion.” He added, “In 1974, Dr. Betkouski sustained a traumatic brain injury, which caused some of his problems to manifest in more concerning ways than they had before.”
According to Cooper, “In 1975, Dr. Betkouski worked for a flavors and fragrances company in the Jacksonville area, and after about three years, concerns mounted after co-workers reported Dr. Betkouski discussing the perfect crime and how cyanide could be used as a less messy means of taking one’s life.” Cooper also said Betkouski was fired by Lockheed in 1982 “following an incident at a local pharmacy,” in which he “attempted to obtain some type of pills or capsules … for an experiment.”
Shared with Chicago police; TV episode teases new material
The Ada County Sheriff’s Office said it has shared its findings with the Chicago Police Department.
More details are slated to air on “Unsolved Mysteries,” in an episode titled “Unmasking the Tylenol Killer” on The Roku Channel on Oct. 9. Series director Terry Dunn-Meurer said the episode includes “never-before-seen evidence about this new possible suspect in the Tylenol murder case.” The show’s official account also promoted the episode in a Sept. 23, 2026 post.
What remains unproven
The sheriff’s office framed the potential tie as a possible link, not a solved case. No suspect has been officially identified in the Tylenol murders.
