DECADES after the eerie Tylenol murders that left seven people dead, including a 12-year-old, new information is still being revealed such as a "handbook of poisons."
Fear and paranoia ripped through the Chicago area in the fall of 1982 after an unknown individual poisoned several bottles of extra-strength Tylenol with lethal doses of potassium cyanide.
Forty years later, the case remains unsolved.
Two Chicago Tribune reporters - Christy Gutowski and Stacy St Clair - interviewed over 150 people across multiple states and reviewed thousands of pages of documents over nine months.
Through their reporting, the duo found that the FBI recorded 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," said Gutowski.
The FBI interview implied that Lewis knew about the Tylenol deaths before they were made public.
Lewis, who worked as a tax consultant, sent a letter to Johnson & Johnson saying that he would stop the murders if he was paid a million dollars.
He was later convicted of extortion and spent 12 years in prison, however, there was never enough evidence to connect him to the poisonings.
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During his trial, Lewis' attorney claimed that he "intended only to focus the attention of the authorities on his wife's former employer."
St Clair said that the FBI went through some of Lewis' stuff and found a "handbook of poisons."
"And in the years since, they have fingerprinted 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’ fingerprint," the reporters said.
Despite it being circumstantial evidence, law enforcement officials want to bring the information to Cook County and DuPage County prosecutors to consider bringing criminal charges.
Lewis and his wife both submitted DNA samples and fingerprints to the FBI in January 2010.
"If the FBI plays it fair, I have nothing to worry about," he said at the time.
Lewis continues to deny any involvement.
PANIC & FEAR
The murders began in September 1982 when 12-year-old Chicago resident Mary Kellerman died after taking Tylenol capsules that had been poisoned.
Mary had woken up that morning with a cold and her parents gave her the painkiller to calm the symptoms, but just hours later she died.
Later that morning, in another Chicago suburb, postal worker Adam Janus collapsed and died too.
While mourning the death of their brother, Adam's brother, Stanley, and his sister-in-law, Theresa, both took painkillers from the same batch and soon died as well.
Hours after Adam, 27-year-old mom Mary Reiner, who had just given birth to her fourth child, felt unwell and took some tablets before collapsing and dying at home.
The same day, Mary McFarland, a 31-year-old shop worker, told her colleagues that she had a bad headache and later died.
Stenographer Diane Elsroth, 23, was staying at her boyfriend's family home in New York when she took a headache pill and went to bed. She was found dead the following day.
When the pills were tested, they were found to contain such a high level of potassium cyanide that they were toxic enough to cause thousands of deaths.
But other than this information, the police were stumped about suspects or motives behind the killings.
The pills had all been made in different production plants and were sold in different pharmacies throughout the Chicago area, without there seeming to be any pattern.
The investigators seemed to think that the culprit had been tampering with the pills while they sat on the shelves of each store.
The deaths set off nationwide hysteria and bottles of Tylenol medication were removed from shops and worried consumers flooded hospitals and poison control helplines with panicked questions.
Unfortunately, the Tylenol murders prompted copycats across the country.
So much so that The Food and Drug Administration in America counted up over 270 different cases of people tampering with products in the month following the murders.
Since the murders, product safety standards in the US were dramatically improved - with tamper-proof seals being added to products.
But whether or not the crimes will ever be solved remains a mystery.