On a September morning, 12-year-old Mary woke up with a headache. Hours later, she was dead. 

On the morning of September 29, 1982, a 12-year-old Chicago girl called Mary Kellerman woke up with a headache and a sore throat. She took some Tylenol painkillers and then collapsed in the bathroom.

“So I opened the bathroom door, and my little girl was on the floor unconscious,” her father Dennis Kellerman told the Chicago Tribune. “She was still in her pyjamas.”

Mary was rushed to hospital, but by 10am that morning, she was declared dead.

That same day, a young, healthy postal worker called Adam Janus took the day off work because he was coming down with a cold. At midday, he picked up his kids from preschool, and on the way home, stopped at the local store to pick up some Tylenol. When he got home, he took a couple of capsules, then collapsed. He could not be revived.

Late that afternoon, Adam’s family were at his house, planning his funeral, when his younger brother Stanley asked for some Tylenol to ease his back pain. His wife Theresa gave him two capsules, then took two herself. He collapsed, then she collapsed.

After a death and two collapses in the same house, Chuck Kramer from the Arlington Heights Fire Department called “the only public health person I know”, a nurse called Helen Jensen. Jensen walked into Adam Janus’ house and took a quick look around. She saw the bottle of Tylenol with six capsules missing and decided that was the cause of death.

“And of course nobody would believe me,” Jensen later told Chicago Magazine. “And I stamped my feet. They said, ‘Oh, no – it couldn’t be. It couldn’t be.’”

An investigator with Cook County’s medical examiner’s officer, Nick Pishos, got a hold of Janus’ Tylenol bottle, as well as the Tylenol bottle from the Kellerman house. His boss, deputy medical examiner Edmund Donoghue, told him over the phone to open both bottles and sniff them. Pishos reported a strong smell of almonds. Both he and his boss knew what that meant: cyanide.

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“I was very lucky because this investigator was able to smell cyanide,” Donoghue remembers. “Only about half the population can smell it.”

By 1am on the morning of September 30, the lab reports came through. The victims had enough cyanide in their blood to kill someone 100 or even 1000 times.

By 10am, a press conference was being held, warning people not to take Tylenol. Chicago police began walking through the streets with loudspeakers to get the message out to even more people.

Sadly, it was too late for Stanley and Theresa Janus. They both died. So did Mary Reiner, a young mum of four, who had given birth just a week earlier. So did Mary McFarland and Paula Prince.

More tainted capsules were discovered on store shelves. The manufacturers, Johnson & Johnson, were able to work out that the contamination had occurred after the Tylenol had left the factory. Police decided that someone must have taken the bottles off store shelves, opened the capsules, laced them with cyanide, put the capsules back in the bottles and put the bottles back on store shelves. At that point, Tylenol was sold in bottles with a simple cap on top.

The tampering inspired copycats around the nation, with more than 270 incidents being reported in the following month.

Rat poison and hydrochloric acid were added to pills. Sodium hydroxide was found in a carton of chocolate milk, and razor blades in frankfurters.

Pins and a sewing needle were discovered inside chocolate bars. That Halloween, trick-or-treating was banned in some communities.

As for Johnson & Johnson, after recalling all Tylenol on sale nationwide, they decided to make some big changes. They brought in tamper-resistant packaging, including foil seals, which soon became standard for over-the-counter painkillers.

They also introduced the caplet, which is harder to tamper with than a capsule.

Food manufacturers also began changing the way they packaged their products, bringing in seals that showed if something had been opened.

Who was behind the Tylenol tampering?

A week after the seven deaths, Johnson & Johnson received a handwritten note demanding that $1 million be deposited in a specified bank account “if you want to stop the killing”. It was discovered that the note had been written by a man called James Lewis. Four years earlier, Lewis had been charged with murder, when human remains had been found in his house, but those charges had been dropped.

In the Tylenol case, Lewis was convicted of trying to extort money from Johnson & Johnson and spent 13 years in jail. But he was not charged over the deaths.

Over the years, many other suspects and motives have been put forward. In all this time, no one has been charged.

“It made no sense,” former Illinois attorney general Tyrone C. Fahner said recently in the New York Times. “There was no clear and intended victim, but just anyone – anyone who happened to have the misfortune to buy a bottle of Tylenol.”