In January 2022, investigative journalists Christy Gutowski and Stacy St. Clair got a phone call they weren't expecting. Their source had an intriguing tip about an unsolved mass murder. Back in 1982, someone put poison on store shelves across the Chicago area. People died at random, sparking a nationwide manhunt and an international panic. Investigators figured out what killed the victims. But the question of who killed them wouldn't be so quick to answer. The FBI spent four decades in a game of cat-and-mouse with one top suspect. But was he the killer? Or could it have been someone else? In Unsealed: The Tylenol Murders, the Chicago Tribune uncovers an active law enforcement investigation into a decades-old case — what may be the last chance to solve it.

In September 1982, people started dying mysteriously in the Chicago area. The victims seemed to have nothing in common. Until a surprising discovery revealed a much bigger mystery. One that wouldn't be so easy to solve.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders.

Investigators raced to find out who committed these random crimes and why. But there was something in their way. And the murder toll climbed. Journalists Stacy St. Clair and Christy Gutowski of the Chicago Tribune find something of their own –– one piece of the puzzle, hiding in plain sight.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders.

A week after the killings, investigators had yet to identify any lead suspects. Until the owner of a bar in Chicago made a phone call. And a mysterious letter arrived at the headquarters of Johnson & Johnson. Law enforcement split in their chase for the Tylenol killer, following two different leads. Plus, a turn in the case when the Tribune reporters get unexpected news about a trusted source.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders/

During the nationwide manhunt, a Kansas City police sergeant unveiled shocking new details about the suspected extortion letter writer. On a flight to Chicago, he brought two suitcases packed with information to share with the Tylenol Task Force about their suspect. He told investigators the story of a different man. Someone who went missing a few years before the Tylenol murders.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders.

Back in 1978, the Kansas City police focused on James Lewis as a suspect in a missing person’s case. A serious mistake during an interrogation would come back to haunt them. But in 1982, that investigation provided valuable insight to the Tylenol task force. And it helped end the weeks-long manhunt for the extortion letter writer. Meanwhile, the Chicago Police’s main suspect, Roger Arnold, proved that he was a killer.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders.

James Lewis was sentenced to prison for the extortion letter. But no one had been charged with the Tylenol murders. Then the FBI got a message. Lewis wanted to talk and help solve the crime. He gave the investigation a creative twist.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders.

The top two suspects spent their lives after prison very differently. But it wouldn’t be long before both were caught up in the Tylenol murders investigation again. This time, one was dead. And one was still alive. During an undercover operation, the FBI hoped one suspect would incriminate himself.

For exclusive details about the Tylenol Murders and a transcript of this episode, visit www.chicagotribune.com/tylenolmurders.