
In 1982, several people in the Chicago, Illinois metropolitan area died after taking the cyanided tainted capsules of the popular non-aspirin pain relief medication Tylenol. Seven victims: 12 year old Mary Kellerman, 27 year old Adam Janus, his brother and sister in law Stanley and Theresa Janus, Mary McFarland Paula Prince and Mary Reiner have never had justice or their killer identified. At one time, there were suspects including one man who was a suspect in a separate murder (though the case was dismissed due to lack of evidence).
On February 8th,1986, Diane Elsroth, a 23 year old stenographer from the town of Peekskill in New York would die from taking a cyanide tainted Tylenol capsule. She was found deceased at her boyfriends house in the city of Yonkers (NY). The bottle which contained the poisoned capsules were purchased at an A&P store in Bronxville. Another tampered bottle of Extra-Strength Tylenol was found at another store in the same city. It has never been proven if her death was connected to the Chicago mass poisonings.
Due to the Tylenol Poisoning, safety standards were vastly improved making many of the medications hard to tamper with. Elsroth’s murder remains unsolved much like the seven other murders in Chicago. Call it terrorism or a serial killing spree. The person(s) responsible for these killings has still never been caught.
A Year Later, Few Clues in Tylenol Poisoning – The New York Times (nytimes.com)