George Trepal and the Coca-Cola Thallium Murder

George Trepal is a Florida chemist and Mensa member who was convicted in 1991 of the Coca-Cola thallium murder of his neighbor Peggy Carr, a poisoning campaign that also sickened six other members of her family in Alturas, Florida. A Polk County jury found him guilty of first-degree murder, six counts of attempted first-degree murder, seven counts of poisoning food or water, and one count of tampering with a consumer product. He was sentenced to death, has exhausted his appeals through the U.S. Supreme Court, and remains on Florida’s death row.¹

What Happened to the Carr Family

In October 1988, members of the Carr family in Alturas began falling ill. Peggy Carr, the matriarch, developed nausea, chest and extremity pain, and difficulty breathing on October 23. Her condition worsened into a coma, and she died on March 3, 1989. Her husband Parealyn “Pye” Carr, their children, Peggy’s daughter Gelena, and her granddaughter Kasey were also poisoned. All of them survived.²

Investigators traced the source to an eight-pack of 16-ounce glass Coca-Cola bottles in the Carrs’ kitchen. Three full bottles and four empties were recovered, and testing confirmed elevated thallium in all seven. The three full bottles held between 403 and 915 milligrams of the poison. The caps on the full bottles showed tiny tool marks, indicating they had been pried off, the contents tampered with, and the bottles resealed with a capping device.² Thallium is tasteless and odorless, and lethal at roughly 14 milligrams per kilogram of body weight, meaning about one gram can kill an average adult.

Why Trepal Targeted His Neighbors

George Trepal and his wife, Dr. Diana Carr, an orthopedic surgeon and no relation to the victims, lived next door to the Carr family. The relationship between the two households was tense. Trepal and his wife complained repeatedly about loud music and other noise, and Trepal reported the Carrs to the local zoning board for converting their garage into living quarters.³

In July 1988, months before anyone got sick, Pye Carr received a typewritten death threat addressed to “Pie Carr” that read: “You and all your so-called family have two weeks to move out of Florida forever or else you all die. This is no joke.”³ When police interviewed Trepal early in the investigation, he offered a comment about the motive: “Someone must have wanted them to move out of the neighborhood.” Investigators later noted the phrasing was “almost identical” to the language in the threat letter.²

The Undercover Mensa Operation

The case against Trepal was built largely through an undercover operation called “Operation Pale Horse,” led by Detective Susan Goreck of the Polk County Sheriff’s Office. In April 1989, investigators learned from a newspaper advertisement that Trepal and his wife were hosting a “Murder Mystery Weekend” at a local Holiday Inn through their Mensa chapter. Trepal belonged to the high-IQ society, and he and Diana were enthusiastic organizers of these role-playing events.⁴

Goreck adopted the alias “Sherry Guin,” posing as a timid newcomer seeking intellectual companionship. She wrote to Trepal, met him on April 14, 1989, and worked her way into his social circle. At the weekend event, participants received a booklet Trepal had prepared that discussed poisoning and threats by neighbors, including the observation: “Few voodooists believe they can be killed by psychic means, but no one doubts that he can be poisoned.”⁵ Prosecutors would later argue that language echoed the letter sent to the Carrs.

Goreck spent months cultivating a friendship. She visited Trepal’s home, sifted through his trash, and arranged social outings to observe him.⁶ When she learned the Trepals were moving to Sebring, she persuaded Trepal to rent her the Alturas house. She moved in during December 1989, and law enforcement now had access to search the property. Goreck also noticed an Agatha Christie novel in the home, The Pale Horse, in which thallium is used as a murder weapon. The book gave the operation its name.⁴

The Bottle in the Garage

On December 12, 1989, crime-scene technicians searched the Alturas property, swabbing drains and surfaces with cotton dipped in nitric acid. FBI Agent Brad Brekke, searching the detached garage, opened a workbench drawer and found a dishpan holding several small bottles. One was a small brown bottle described as being “literally part of a rat’s nest.”⁷

Sent to the FBI Laboratory in Virginia and labeled specimen Q206, the bottle held approximately 640 milligrams of a beige, dirty-white crystalline powder. Analyst Donald Havekost confirmed the presence of thallium, and examiner Roger Martz identified the substance as thallium I nitrate.⁵ Trial witnesses testified that Trepal had told people he was a chemist, that he intended to set up a laboratory in that garage, and that he owned brown bottles similar to the one recovered. Trepal was arrested on April 7, 1990.

Trial and Death Sentence

Trepal’s trial took place in Polk County’s 10th Judicial Circuit, with more than 70 witnesses testifying for the prosecution. The case was largely circumstantial. Prosecutors argued that Trepal, a chemist with a prior conviction for manufacturing illegal drugs,⁶ had poisoned his neighbors’ Coca-Cola with thallium to drive them off. The evidence combined the poisoned bottles, the thallium nitrate in the garage, the murder mystery booklet, and the undercover work.

On February 5, 1991, the jury found Trepal guilty on all counts.⁴ The jury recommended death by a 9-to-3 vote, and on March 6, 1991, Judge Dennis P. Maloney sentenced him to death for Peggy Carr’s murder, with concurrent 30-year sentences on the remaining 14 counts.¹ Diana Carr was never charged.⁸

The FBI Lab Problem

Years after the trial, the forensic evidence became a serious point of contention. In 1997, the U.S. Department of Justice’s Office of the Inspector General issued a report sharply criticizing the work of FBI examiner Roger Martz, whose testimony the Herald-Tribune described as “the only direct evidence of guilt” tying the thallium in the Coca-Cola to the thallium in Trepal’s garage.⁹

The OIG found Martz’s testimony was “stronger than his analytical results would support.” He could properly have said the Coca-Cola samples were “consistent with” the addition of thallium nitrate, but he told the jury flatly that thallium nitrate had been added. He testified to running ion chromatography on all three Coca-Cola samples when he had never actually tested sample Q3. Other tests, including mass spectrometry and x-ray powder diffraction, had not identified thallium nitrate, and he did not acknowledge that. His claim that the garage powder was “greater than 95 percent pure” thallium nitrate lacked an analytical basis, his case notes were “incomplete, undated and inaccurate,” and he never ran the straightforward validation of spiking unadulterated Coca-Cola with thallium nitrate to see how it behaved.¹⁰ The OIG called Martz’s conduct “particularly disturbing” given that Trepal had been sentenced to death, and recommended he be removed from any supervisory role.¹¹

The criticism was directed at Martz’s work, not at Donald Havekost’s separate analysis, which established the presence of thallium in the samples. The underlying finding that the Coca-Cola bottles contained lethal quantities of thallium was not disputed.

Trepal used the OIG findings to reopen his case, adding a claim under Giglio v. United States, which bars the prosecution from knowingly using false testimony. At evidentiary hearings in 1999, FBI whistleblower Dr. Frederic Whitehurst and Dr. Marland Dulaney testified that Martz’s data supported only the presence of nitrate, not the definitive identification of thallium nitrate. Martz himself conceded that his trial testimony was inaccurate and that the data was only “consistent with” that conclusion.¹² The state trial court found that some of the testimony was false but held it had not prejudiced Trepal enough to warrant a new trial. The Florida Supreme Court affirmed, and the U.S. Supreme Court denied review in October 2003.¹

Trepal then sought federal habeas relief. The Eleventh Circuit affirmed the denial on June 19, 2012, assuming for argument’s sake that a Giglio violation had occurred but ruling that Trepal had not suffered “actual prejudice” because the remaining evidence of guilt was overwhelming.⁵ The U.S. Supreme Court declined to hear the case a final time on March 18, 2013.¹³

Where the Case Stands Now

With his appeals exhausted, Trepal’s case moved into Florida’s executive clemency process. As of early 2016, the governor’s clemency office had contacted Peggy Carr’s surviving son, Duane Dubberly, as part of its investigation.¹⁴ A Petition for Executive Clemency was filed on Trepal’s behalf, addressed to Governor Rick Scott and the Florida Executive Clemency Board, asking that no death warrant be signed.¹⁵ No execution warrant had been signed as of that time. Trepal remains on death row.

1
Florida Legislature. Trepal Capital Case Update
2
Findlaw. Trepal v. Secretary Florida Department of Corrections
3
MagellanTV. Malice and Mensa: Why Was Peggy Carr Murdered
4
Sun Sentinel. The Mensa Murder
5
U.S. Court of Appeals for the Eleventh Circuit. Trepal v. Secretary, Florida Department of Corrections
6
Tampa Bay Times. Murder on the Mind
7
Florida State University Law Library. George James Trepal v. State of Florida
8
Tampa Bay Times. Suspect Used Poison Before, Officials Say
9
Herald-Tribune. Lab Work Becomes Issue in Fatal Poisoning Appeal
10
DOJ Office of the Inspector General. The FBI Laboratory: An Examination Into Laboratory Practices and Alleged Misconduct in Explosives-Related and Other Cases – Trepal
11
DOJ Office of the Inspector General. OIG Report on FBI Laboratory – Trepal Case
12
Findlaw. Trepal v. State
13
U.S. Supreme Court. Docket No. 12-8208, George James Trepal v. Michael D. Crews
14
The Ledger. Polk Murderers in Line for Death Warrants
15
Squarespace. Petition for Executive Clemency in a Capital Case – George Trepal