The Poisoning of Peggy Carr

In the fall of 1988, 41-year-old Peggy Carr from Alturas, Florida, suddenly fell ill with symptoms that baffled doctors. It began with tingling in her legs and burning pain in her feet. Within days, she could barely walk. Her hair began to fall out. Her speech slurred. Her vision blurred.

Doctors suspected everything from a viral infection to stress. But nothing explained the rapid deterioration of her health — until two of her sons developed the same mysterious symptoms.

When toxicology tests came back, the truth shocked everyone: the Carr family had been poisoned with thallium, a highly toxic metal once used in rodenticide before being banned in the U.S. in 1972.

A Forensic Mystery

Health officials launched a massive environmental investigation, testing everything from the family’s well water to nearby orange groves. Nothing turned up.
Then, during a sweep of the Carr home, investigators found several bottles of Coca-Cola contaminated with thallium. Someone had tampered with the bottles — opening them, adding poison, then carefully resealing the caps.

The discovery transformed the case from a medical mystery into a criminal investigation.

The Profile and the Neighbor

The FBI’s Behavioral Science Unit built a psychological profile of the killer: an intelligent, white male in his 30s or 40s, methodical, controlling, and fascinated by murder. A man who resolved conflict indirectly — someone who might turn to poison instead of confrontation.

That description fit George Trepal, the Carr family’s only neighbor. Trepal was a chemist, a member of Mensa, and married to a physician, Dr. Diana Carr (no relation). Detectives soon discovered his criminal past — an arrest in the 1970s for running a meth lab. One officer described him as “the smartest chemist I’ve ever met.”

The Undercover Operation

With no direct evidence tying Trepal to the poisoning, investigators sent undercover agent Susan Goreck to infiltrate the Mensa group George and Diana belonged to.

At a “Murder Mystery Weekend” hosted by the Trepals, Goreck received one of George’s game packets — a fictional murder story involving a victim poisoned to death.

Over the next year, Goreck befriended George, eventually renting his old home after he and Diana moved. Once she moved in, detectives searched the property. In a small workshop shed, they discovered a chemical bottle containing thallium, identical to the compound found in the Carrs’ Coke bottles.

Inside Trepal’s new home, police found a notebook labeled “General Poisoning Guide,” with handwritten notes on lethal toxins — including thallium.

Justice for Peggy Carr

In 1991, George Trepal was tried for the murder of Peggy Carr and the attempted murder of her family. The jury found him guilty on all counts. He was sentenced to death, plus multiple life terms.

To this day, Trepal maintains his innocence, but his appeals have been repeatedly denied.

Peggy Carr’s case remains one of the most haunting examples of how forensic toxicology can uncover the truth when traditional evidence fails.

Listen to the Full Story

Hear the full case — including exclusive forensic details and insight into the investigation — on this week’s episode of Forensic Tales, The Poisoning of Peggy Carr.

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