Stella Nickell

During an autopsy on Snow, Assistant Medical Examiner Janet Miller detected the scent of bitter almonds, an odor distinctive to cyanide.[5] Tests verified that Snow had died of acute cyanide poisoning.[2] Investigators examined the contents of the Snow-Webking household and discovered the source of the cyanide: the bottle of Excedrin capsules that both Snow and Webking had used the morning of Snow's death. Three capsules out of those that remained in the 60-capsule bottle were found to be laced with cyanide in toxic quantities.[7]

A murder by cyanide was sensational news in Washington state. When another tainted bottle from the same lot was found in a grocery store in nearby Kent, Bristol-Myers, the manufacturers of Excedrin, responded to the discovery with a heavily publicized recall of all Excedrin products in the Seattle area,[8] and a group of drug companies came together to offer a $300,000 reward for the capture of the person responsible.[5]

In response to the publicity, Stella came forward on June 19. She told police that her husband had recently died suddenly after taking pills from a 40-capsule bottle of Excedrin with the same lot number as the one that had killed Snow.[2] Tests by the Food and Drug Administration (FDA) confirmed the presence of cyanide in her husband's remains and in two Excedrin bottles Stella had turned over to police.[5][7]

Initial suspicions were directed at Bristol-Myers, with Stella and Webking filing wrongful death lawsuits against the company.[3] The FDA inspected the Morrisville, North Carolina, plant where the tainted lot had been packaged, but found no traces of cyanide to explain its presence in the Washington bottles.[7] On June 18, Bristol-Myers recalled all Excedrin capsules in the United States, pulling them from store shelves and warning consumers to not use any they may already have bought;[7] two days later the company announced a recall of all of their non-prescription capsule products.[9] On June 24, a cyanide-contaminated bottle of Anacin-3 was found at the same store where Snow had bought her contaminated Excedrin.[5] On June 27, Washington state put into effect a 90-day ban on the sale of non-prescription medication in capsules.[9]

Examination of the contaminated bottles by the FBI Crime Lab found that, in addition to containing cyanide powder, the poisoned capsules also contained flecks of an unknown green substance.[2] Further tests showed that the substance was an algaecide used in home aquariums, sold under the brand name Algae Destroyer.[6]

With contamination of the Excedrin at the source having been ruled out, investigators began to focus their investigation on the end-users of the product. The FBI began an investigation into possible product tampering having been the source of the poison. At the time, Excedrin was packaged in plastic bottles with the mouth of the bottle sealed with foil and the lid secured to the bottle with plastic wrap.[7]

Both Stella and Webking were asked to take polygraph examinations. Webking did so, but Stella, who had started drinking heavily,[2] declined. A lawyer representing Stella told reporters that she was too "shaken up" to be subjected to the examination.[9] Investigators' suspicions began to turn to Stella when they discovered that she claimed that the two contaminated Excedrin bottles that she had turned over to police had been purchased at different times and different locations.[2] A total of five bottles had been found to have been contaminated in the entire country, and it was regarded as suspicious that Stella would happen to have acquired two of them purely by chance.[10]

With investigatory focus turned to Stella, detectives uncovered more circumstantial evidence pointing to her as the culprit. She had taken out a total of about $76,000[11][note 2] in insurance coverage on her husband's life, with an additional payout of $100,000 if his death was accidental.[2] She was also known to have, even before Snow's death, repeatedly disputed doctors' ruling that her husband had died of natural causes.[6] Further FBI investigation showed that Bruce's purported signatures on at least two of the insurance policies in his name had been forged.[5] Investigators were also able to verify that Stella had purchased Algae Destroyer from a local fish store; it was speculated that the algaecide had become mixed with the cyanide when Stella used the same container to crush both substances without washing it in between uses.[1][2]

Stella finally consented to a polygraph examination in November 1986. She failed and investigators narrowed their focus to her even further.[6] Concrete evidence proving that she had ever purchased or used cyanide was lacking, and despite their relative certainty that she had orchestrated the poisonings as either an elaborate cover-up for an insurance-motivated murder of her husband or a desperate attempt to force her husband's death to be ruled an accident to increase her insurance payout, they were unable to build a strong case supporting arrest.[1] Further proof of Stella's involvement was determined when her name was found on library records showing she borrowed a book on botany, which contained a chapter about poisonous plants.

In January 1987, Stella's now-grown daughter, Cynthia Hamilton, approached police with information: her mother had spoken to her repeatedly about wanting Bruce dead, having grown bored with him after he quit drinking.[5] Stella, Hamilton claimed, had even told her that she had tried to poison Bruce previously with foxglove hidden in capsules.[6] Bruce had taken them to no effect save for complaining of sudden drowsiness. Following that failure, Stella had begun library research into other methods and hit upon cyanide.[1] Hamilton also claimed that Stella had spoken to her about what the two of them could do with the insurance money if Bruce was dead.[5]

Records from the Auburn Public Library, when subpoenaed, showed that Stella had checked out numerous books about poisons, including Human Poisonings from Native and Cultivated Plants and Deadly Harvest.[2] The former was marked as overdue in library records, indicating that she had borrowed but never returned it.[12] The FBI identified her fingerprints on cyanide-related pages of a number of the works she had checked out during this period.[1] By the summer of 1987, even Stella's attorneys acknowledged that she was the prime suspect in the case.[13]