A man who died from cyanide poisoning in an Idaho church in 1982 has been identified as Dr Mathew Francis Betkouski, an organic chemist. Investigators say his background and comments about poison have raised questions about a possible link to the unsolved Chicago Tylenol murders, but they have not named him as a suspect or established that he was in Chicago when the poisonings occurred.

Betkouski died unidentified in Boise on 4 December 1982 after entering Sacred Heart Catholic Church. DNA testing linked him to his family, while investigators found a Chicago map, sodium cyanide and accounts of his discussions about poisoning capsules; however, the chemical differed from that used in the Tylenol deaths. Authorities have shared their findings with Chicago-area investigators and are seeking information about his movements and communications.