When does Painkiller: The Tylenol Murders return?

The Chicago Tylenol murders were a series of poisoning deaths resulting from drug tampering in the Chicago metropolitan area in 1982. The victims consumed poisoned pills laced with potassium cyanide. At least seven people died in the original poisonings, and there were several more deaths in subsequent copycat crimes. The incidents led to reforms in the packaging of over-the-counter drugs and to federal anti-tampering laws.