Idaho man who died of cyanide in 1982 identified as Dr. Mathew Betkouski, possible link to Tylenol murders

Authorities in Ada County, Idaho, announced Wednesday that the man long referred to as the "Unknown Wanderer" was Dr. Mathew Francis Betkouski, an organic chemist who died of cyanide poisoning after entering Sacred Heart Catholic Church in Boise on Dec. 4, 1982. The identification was made through DNA genealogy after investigators linked a key found on the body to a residence in Jacksonville, Florida, and confirmed the match with a sample from Betkouski's brother.

Betkouski's belongings included a map of Chicago and a bottle of sodium cyanide, and former colleagues recalled him discussing the "perfect crime" and the possibility of introducing poison into over-the-counter capsules. While the sodium cyanide differs from the potassium cyanide used in the 1982 Chicago Tylenol poisonings, investigators said the details warrant further review.

Forensic psychiatrist Dr. Park Dietz, who consulted on the original Tylenol case, said that anonymous panels of forensic experts who reviewed Betkouski's profile "overwhelmingly considered him a viable suspect." He added that the new information may bring closure to a decades-old investigation.

Betkouski vanished from his New Mexico home on Oct. 15, 1982, and was found dead in Boise seven weeks later after apparently altering his appearance. Authorities have forwarded their findings to investigators in Chicago and are seeking additional information about his movements and communications in 1982. Ada County Sheriff Matt Clifford said the inquiry remains open.