Sue Snow suddenly collapsed on June 11, 1986, in the bathroom of her home in the Seattle, Washington, suburb of Auburn. Paramedics found her unconscious and gasping for breath. They transported her to the hospital, where she soon died. One possible explanation for the young woman's death was a drug overdose, but she was not a known user and had taken only a couple of Extra-Strength Excedrin, a safe medication.
During her autopsy, examiners noticed a faint odor of almonds emanating from the corpse. A toxicology exam revealed the presence of cyanide. An examination of the Excedrin capsules followed, and they too tested positive for cyanide.
The Food and Drug Administration (FDA) and the manufacturer, Bristol-Meyers, moved quickly to remove all Extra-Strength Excedrin bottles from shelves across the country. Seattle police found two other contaminated bottles, one in Auburn and the other in nearby Kent.
In a separate turn of events, Stella Nickell told police on June 17 that her husband had died suddenly just a few days earlier and that he too had taken Excedrin. Already buried, Bruce Nickell's death certificate stated that he'd died of emphysema. However, because he was a registered organ donor, a sample of his blood had been retained, making an exhumation unnecessary. Tests done on his blood sample showed that he too died from ingesting cyanide.
While police searched for a connection between Sue Snow and Bruce Nickell, the FDA examined more than 740,000 Excedrin capsules from the Pacific Northwest and Alaska. They found cyanide in only five bottles, two of which were in the possession of Stella Nickell. Asked whether she bought the bottles at the same time and from the same store, she said no, she had purchased them on different days at different stores. The odds against such bad luck are astronomical.
In addition to cyanide, FDA examiners detected another odd chemical in the contaminated capsules: traces of an algaecide known as Algae Destroyer, which is used in fish tanks. Stella Nickell had a fish tank and immediately became the focus of the investigation. An in-depth look into her background revealed that she had a history of forgery, fraud, and child abuse. In addition, she had purchased extra insurance on Bruce that would pay her $176,000 in the event of an accidental death.
Stella Nickell denied any involvement in the product tampering but failed a polygraph examination. Then her own daughter came forward, telling police that her mother had often mentioned killing Bruce, even going so far as indicating that she'd researched the use of cyanide.
This information led police to the local Auburn library, where they discovered that a book Stella had checked out was overdue. The title? Human Poisoning. They also found that she had twice checked out Deadly Harvest, a book on toxic plants. At the FBI crime lab, 84 of Stella's fingerprints were found on the book's pages. Most of them were found in the section dealing with cyanide.
On May 9, 1988, Stella was sentenced to a 99-year prison term.