Cold Case: The Tylenol Murders

After cyanide-laced Tylenol kills multiple people across Chicago, police and the media scramble to spread a nationwide warning.

A key suspect maintains his innocence, even as authorities discover his suspicious past and possible motive. Tylenol unveils new triple-seal packaging.

Decades after the murders, a victim's daughter searches for justice — and uncovers forgotten evidence that supports a controversial theory.