Stella Nickell and the Excedrin Murders: How Cyanide-Laced Capsules Killed Two Innocent People

In the 1980s, Americans were terrified of product tampering.

The 1982 Chicago Tylenol murders had shaken public trust in over-the-counter medication. Seven people died after taking cyanide-laced capsules, and the crime was never solved. Tamper-evident packaging became the new standard — but fear lingered.

Then in 1986, history seemed to repeat itself.

This time, it happened in Washington State. And this time, forensic science would uncover the truth.

The Sudden Death of Bruce Nickell

On June 5, 1986, 52-year-old Bruce Nickell returned home from work complaining of a severe headache. He did what many of us would do — he reached for extra-strength Excedrin.

He took four capsules.

Within minutes, he collapsed on his front porch.

Bruce was rushed to Harborview Medical Center in Seattle but was pronounced dead shortly after arrival. Initially, doctors believed he had died from natural causes — possibly emphysema or COPD — despite no known history of serious illness.

No one suspected poison.

A Second Victim Changes Everything

Six days later, 40-year-old bank manager Sue Snow woke up with a headache and took two extra-strength Excedrin capsules before brushing her teeth.

She never walked out of the bathroom.

Her teenage daughter found her unconscious on the floor. Sue was transported to the same hospital where Bruce had died days earlier — and she too was pronounced dead.

This time, an autopsy was performed.

Before even beginning the internal examination, the medical examiner noticed a distinct odor — bitter almonds — often associated with cyanide poisoning.

Toxicology confirmed it.

Sue Snow had died from acute cyanide poisoning.

Suddenly, Bruce Nickell’s death looked very different.

Cyanide-Laced Excedrin

Police returned to Sue’s home and collected the open bottle of extra-strength Excedrin found in her bathroom. Testing revealed that three remaining capsules were contaminated with lethal quantities of cyanide.

Investigators exhumed Bruce’s body and tested the Excedrin bottles from his home.

The results were shocking.

Bruce had also died from cyanide poisoning.

Authorities now had two victims — and five contaminated Excedrin bottles identified nationwide.

The FBI and FDA joined the investigation. Bristol-Myers, Excedrin’s manufacturer, issued massive recalls. Washington State temporarily banned the sale of non-prescription capsule medications.

Public panic spread rapidly.

The Forensic Break: Green Flecks Inside the Capsules

For weeks, investigators searched for a suspect.

The breakthrough came from the FBI Crime Lab.

Inside some of the contaminated bottles, analysts found tiny green flecks mixed in with the cyanide powder. Testing identified the substance as an aquarium algaecide sold under the brand name Algae Destroyer.

That detail would become critical.

Investigators discovered that Stella Nickell — Bruce’s wife — had recently purchased a large quantity of the same product from a local pet store. The store manager remembered her clearly because he had to special-order the amount she requested.

The FBI theorized that the algaecide became mixed with the cyanide when the same container was used to crush both substances without being cleaned in between.

Trace evidence — microscopic contamination — had linked the poison to Stella.

Suspicious Insurance Policies

Investigators also uncovered a potential financial motive.

Stella had taken out approximately $75,000 in life insurance policies on Bruce. If his death were ruled accidental, she would receive an additional $100,000 payout.

Before Sue Snow’s death connected the cases, Stella reportedly pushed for Bruce’s cause of death to be classified as accidental rather than natural.

Authorities also found evidence that Bruce’s signature had been forged on insurance documents.

But prosecutors believed Bruce wasn’t the only intended victim.

Why Was Sue Snow Targeted?

According to the prosecution’s theory, Sue Snow was not the intended target.

She was collateral damage.

Prosecutors alleged that Stella had poisoned multiple Excedrin bottles and returned some of them to store shelves to make the crime appear random — similar to the unsolved Chicago Tylenol murders.

If Bruce had been the only victim, suspicion would likely have fallen on his wife.

But multiple victims suggested a nationwide tampering incident.

That strategy nearly worked.

Additional Evidence: Library Records and Witness Testimony

Stella’s daughter, Cynthia Hamilton, later contacted the FBI and reported that her mother had previously spoken about wanting to kill Bruce.

Investigators confirmed that Stella had borrowed — and never returned — a book titled Human Poisoning from the Auburn Public Library. Her fingerprints were found on multiple books about cyanide.

Stella claimed she had researched poisons to investigate potential issues with her garden.

A jury would ultimately decide which explanation they believed.

Trial and Conviction

In December 1987, Stella Nickell was indicted on five federal counts of product tampering, including two resulting in death.

In May 1988, after five days of jury deliberation, she was found guilty on all charges.

She was sentenced to 90 years in federal prison.

As of 2024, she remains incarcerated at FCI Hazelton in West Virginia and is scheduled for release in 2043.

The Power of Forensic Science

This case was not solved by a confession.

It was solved through:

Trace chemical analysis
Probability assessment of bottle purchases
Life insurance documentation
Library records
Purchase tracking of specialty aquarium chemicals

Stella Nickell believed she could stage randomness — recreating the fear of the Chicago Tylenol murders.

But forensic science found patterns.

The microscopic green flecks inside the capsules told a story she couldn’t erase.

Two innocent people — Bruce Nickell and Sue Snow — lost their lives after taking medication intended to relieve pain.

And ultimately, it was forensic evidence that brought justice.

Listen to the Full Episode

If you want a deeper forensic breakdown of this case — including trial details, appeals, and Stella’s continued claims of innocence — listen to the full episode of Forensic Tales wherever you get your podcasts.

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