Diane Elsroth

On February 8, 1986, 23-year-old Diane Elsroth took two Extra-Strength Tylenol capsules at the home of her boyfriend in Yonkers, New York. She collapsed almost immediately and was rushed to the hospital, where she died. Toxicology tests revealed she had ingested capsules laced with potassium cyanide—echoing the terrifying Chicago Tylenol murders of 1982.

The discovery triggered immediate action. Johnson & Johnson, the parent company of Tylenol, pulled all capsule products from shelves nationwide and announced it would permanently discontinue the sale of over-the-counter capsule medications, switching entirely to solid caplets that were far more difficult to tamper with. The FDA tested thousands of bottles from the region and found a second contaminated bottle at a store in Bronxville, New York.

The investigation by the FBI, FDA, and Westchester County authorities was extensive. Unlike the 1982 Chicago poisonings, where the contamination appeared widespread, the 1986 incident seemed more targeted—only two contaminated bottles were found, both in Westchester County. Investigators examined whether the tampering occurred at the retail level or during distribution.

Despite years of investigation, no one was ever charged in the 1986 Tylenol poisoning. The case, like the 1982 Chicago murders, demonstrated the vulnerability of consumer products to tampering and led to permanent changes in pharmaceutical packaging across the industry. Diane Elsroth's death remains an unsolved homicide.