Nancy Dillard Lyon had everything a person could want, or so it seemed. By thirty-seven, she had a successful career, two daughters, and a home in an upscale Dallas neighborhood. But on the evening of January 8th, 1991, that perfect life began to unravel when she collapsed with violent stomach pain. Her husband Richard called her doctor, who suspected food poisoning.
Nothing helped. At the hospital, Nancy’s condition worsened by the hour. Her blood pressure dropped. Her breathing became erratic.
Her organs started failing. The doctors were baffled. While she was still conscious, Nancy made a desperate confession to one of the doctors. She believed someone was poisoning her.
She told him about strange incidents that had started four months earlier, beginning with a bottle of expensive wine left on her porch with no note. She took a few sips, tasted something terrible, and became violently ill. She assumed the wine had gone bad, but later noticed the bottle looked like it had already been opened. What she didn’t yet mention was her suspicion about who might be behind her illness.
Before Nancy lost consciousness, she told the same story to her attorney, Mary. There was more, she said. Months earlier, she and Richard had gone to a movie as part of their effort to save their marriage. At the theater, Richard brought her a soda.
When she sipped it, she tasted something strange and saw a white powder dissolving in the drink. Richard insisted nothing was wrong and grew angry when she refused to finish it. That night, she became extremely sick again. Nancy had also told Mary about the vitamins Richard kept giving her.
He claimed they would improve her health, but he never showed her the bottle or packaging. She had kept the capsules, along with the wine bottle, hidden away. She refused to test them, though. Accusing her husband of poisoning her would cause a scandal, and Nancy had been raised to protect the family’s reputation at all costs.
Mary heard about Nancy’s hospitalization and called her father immediately. He brought the wine and capsules to the hospital, and doctors rushed them to a laboratory. Nancy’s blood samples were already being tested for toxins. But it was too late.
Six days after she was admitted, Nancy died. The autopsy revealed no natural cause of death. Her body had been sent to the medical examiner because doctors strongly suspected foul play. The wine tested clean.
The capsules, however, contained barium carbonate, a toxic industrial chemical. But when Nancy’s toxicology results came back, they showed something different entirely. The poison in her blood was arsenic, at levels many times higher than normal. It had destroyed her organs.
Investigators sent strands of Nancy’s hair to a chemistry professor. Hair grows outward from the root, so each segment reveals a timeline of exposure. The professor found at least three separate arsenic exposures. The most recent, and most concentrated, had occurred about two weeks before Nancy’s death.
Detectives kept their findings secret. They waited nearly six weeks before questioning Richard, who had recently returned from a vacation in Mexico with his mistress, a trip taken shortly after Nancy’s funeral. Richard denied everything. He claimed he had purchased arsenic and cyanide the previous summer to deal with fire ants in the backyard.
He said he never used the chemicals and threw them away. He agreed to let detectives search his house and car, and they found nothing. His financial records told a different story. In August 1990, Richard had ordered barium carbonate, the same chemical found in the capsules Nancy was taking.
In late November, he purchased large quantities of several arsenic compounds, spending nearly three hundred dollars. Some packages were delivered to his workplace, but the August shipment went to the apartment he rented while separated from Nancy. A neighbor in that building remembered accepting hazardous chemical deliveries for Richard. Inside the apartment, detectives found a bag of empty capsules meant to be filled by hand, along with a bottle of vitamins.
Still, there wasn’t enough for an arrest. In mid-March, police held a press conference announcing the case as a homicide and naming Richard as the prime suspect. The story exploded across national news. Richard held his own press conference the next day, offering three alternative theories.
First, Nancy was scheduled to testify against a former boss accused of stealing money. She had received anonymous threats. Investigators questioned the boss, but found nothing linking him to the crime. Second, Richard suggested Nancy might have been poisoning herself to win his sympathy and keep him from divorcing her.
Perhaps she accidentally took too much. Third, and most disturbing, he blamed Nancy’s brother Bill. Richard gave police a collection of notes he claimed Nancy had written after therapy sessions. The notes described years of abuse from Bill, describing him as jealous, aggressive, and dangerous.
Bill owed Nancy nearly ninety thousand dollars. Detectives interviewed Nancy’s parents, who admitted something inappropriate had happened between brother and sister years earlier but insisted Nancy exaggerated it. Bill denied everything. The case took an even stranger turn when police received an anonymous letter from someone claiming to be a hired killer.
The writer said Bill had paid him to murder Nancy, but after Bill refused to pay, the killer decided to confess. The letter was typed, offering no fingerprints or handwriting. The lead evaporated. Then investigators made a discovery that unraveled Richard’s entire defense.
They sent Nancy’s notes to a handwriting expert. Initially, all the entries appeared to be written in the same hand. But further analysis revealed Nancy and Richard had deliberately learned to write alike in college so Nancy could complete assignments for him without detection. The expert found small but consistent differences.
Nancy had written most of the notes, but every passage about Bill had been added by Richard. Five months after Nancy’s death, Richard was arrested for murder. The prosecution’s case came together like a tight knot. Richard had slowly poisoned Nancy with small doses of multiple chemicals, creating a history of mysterious illnesses that would explain her eventual death.
His motive was money. Nancy earned far more than he did. A divorce would cost him his comfortable lifestyle and force him to support their two daughters. But if Nancy died, he would inherit her savings, collect five hundred thousand dollars from her life insurance policy, and start a new life with his mistress.
Richard’s mistress unknowingly incriminated him. She told investigators that Richard had claimed Nancy was dying from a rare blood disorder, months before Nancy ever became seriously ill. He had also promised to marry his mistress, even while claiming to work on saving his marriage. The defense offered nothing that stuck.
Richard claimed to have found an invoice showing Nancy purchased arsenic herself, with her signature on it. The owner of the company testified that his business never sold those chemicals and used completely different invoices. The document was a forgery. A psychiatrist who never met Nancy testified she may have poisoned herself for attention.
Prosecutors countered with a simple question. When Nancy was hospitalized, she begged the doctor not to let her die. If she had knowingly taken poison, why wouldn’t she name it and give the doctors a chance to save her? The jury convicted Richard of murder.
He was sentenced to life in prison plus a ten thousand dollar fine. Years of appeals went nowhere. In 1994, an appeals court ruled the evidence against Richard was overwhelming. Nancy’s daughters were taken in by her family after Richard’s arrest.
And there was one final quiet act of protection from their mother. After Nancy began suspecting Richard, she changed the beneficiary on her life insurance policy. The five hundred thousand dollar payout went to her daughters, not her husband. Even if he had walked free, he would never have seen that money.
Richard remains in prison today. He became eligible for parole in 2006 and was denied. He tried again in 2016, then once more in the spring of 2026. Each time, the board refused, partly because he continues to deny any responsibility for his wife’s death.
At nearly seventy years old, Richard will likely spend the rest of his life behind bars.
