Overview
- Ada County announced Wednesday that the long-unidentified man found dead in a Boise church in December 1982 is Dr. Mathew Francis Betkouski after tracing an engraved key and confirming family DNA.
- Investigators recovered personal items including photos, maps and a small bottle of homemade sodium cyanide from Betkouski’s effects and used those items to build a lead that they say could relate to the Tylenol killings.
- Ada County emphasized the link is tentative because the substance found in Idaho was sodium cyanide, which differs chemically from the potassium cyanide used in the Chicago deaths, and because they cannot place Betkouski in Chicago during the September 1982 killings.
- Officials have sent their files to the Arlington Heights task force, Chicago police and the FBI, who say they have reviewed the material but have not named Betkouski a suspect and continue to treat the Tylenol case as open.
- The Tylenol murders killed seven people and prompted tamper‑evident packaging rules, and this new identification may prompt fresh vetting, public tips and documentary attention as lead investigators weigh the evidence.