When does Cold Case: The Tylenol Murders return?

Tylenol is a brand of medication, advertised for reducing pain, reducing fever, and relieving symptoms of allergies, cold, cough, headache, and influenza. The active ingredient in the brand is acetaminophen (paracetamol), an analgesic and antipyretic. The brand was introduced in 1955 by McNeil Laboratories, a family-owned pharmaceutical manufacturer. In 1982, seven people died in Chicago after ingesting cyanide-contaminated pills laced with cyanide.