CHICAGO -- Decades ago, seven people in the Chicago area died after taking cyanide-laced capsules of Extra Strength Tylenol and on the 20th anniversary of the first death, police are still looking for the killer.

Seemingly random deaths in 1982 turned into a murder mystery when authorities realized that some people who had recently died took Tylenol. Lab results confirmed that the Tylenol had been spiked with the deadly chemical. The fallout caused nationwide panic and eventual reforms in how companies package products.

The first victim was a 12-year-old girl seeking to cure a morning headache. She died 20 years ago Sunday.

Officials investigated more than 400 possible suspects and followed thousands of leads, but found nothing.

The victims' family and friends and those involved with the original investigation are coming to terms with the fact that, despite the initial frenzy, there is little law enforcement can do now unless it gets a lucky break.

Two men were convicted for crimes related to the 1982 poisonings: Roger Arnold of Chicago for killing a man he thought directed investigators his way in the case, and James E. Lewis of Kansas City, who sent an extortion note to Johnson & Johnson threatening to poison bottles of the painkiller unless he got $1 million.

Some investigators believed Lewis was also the killer but it was never proven.