CHICAGO (WGN) – September marks the 40th anniversary of the “Tylenol Murders” – seven Chicago-area poisoning deaths linked to tainted vials of the popular over-the-counter medicine.

To this day, it remains unsolved. 

It was the fall of 1982 and the mystery gripped the nation in anxiety and fear. Someone poisoned extra-strength Tylenol, the best-selling pain reliever in America, with lethal doses of potassium cyanide.  

The person responsible was never arrested and the public grappled with a wave of fear over tampering with everyday products at grocery stores.

But Chicago Tribune investigative reporters have uncovered new information that shows the case is still being actively investigated and some law enforcement officials say there’s enough circumstantial evidence to bring charges against the prime suspect.   

Chicago Tribune investigative reporters Christy Gutowski and Stacy St. Clair have conducted a nine-month long investigation into the mystery surrounding the murders – interviewing 150 people across multiple states and reviewing tens of thousands of pages of documents.  

 “It’s an active investigation,” Gutowski said. “Investigators just got back in Illinois (Thursday) from being in Boston, the Cambridge area and interviewed Jim Lewis, the prime suspect.”

Their reporting reveals the FBI recorded a video of prime suspect James Lewis during a sting operation.

 “We were able to look at undercover FBI video that was taken in 2007 right here in Chicago at the Sheraton Hotel,” Gutowski said.

The FBI interview indicates that Lewis knew about the Tylenol deaths before they were made public.    

Lewis was a tax consultant who sent a letter to Johnson & Johnson and said he would stop the killing if the company paid him a million dollars. He was convicted of extortion and spent 12 years in prison. But investigators never found hard evidence to tie him to the poisonings.  

“They went through some of his stuff and found the handbook of poisons,” St. Clair said. “And in the years since, they have finger printed that book and on page 196, the page that includes information on how much cyanide is needed for a fatal dose in the average human, they found Jim Lewis’s fingerprint.”

It’s circumstantial evidence, but law enforcement officials say they’re bringing it to Cook County and DuPage County prosecutors so they can consider bringing criminal charges 40 years after the Tylenol Murders.