The Effect
It is a regular morning in early summer, 1986, and in the US city of Auburn, people are beginning to rise from their beds and prepare to make their journeys to work.
40 year-old local bank manager, Susan Snow, is no different. Sue, as she is known, has woken early and, finding herself suffering from a headache, quickly reaches for a couple of painkillers before jumping in the shower. Elsewhere in the same house, Sue’s 15 year-old daughter Hayley is getting ready to leave for school. But just as she does, she hears a strange and sudden thud come from the bathroom. Hayley races in to find her mother, slumped on the floor of the shower, completely unresponsive, her eyes glazed.
Hayley rushes for help, and Sue is airlifted to hospital. But only hours later, medical staff give the family the devastating news. Sue’s brain is no longer functioning and, as a result, her life support machines are being switched off. She had passed out as she got into her shower, and never regained consciousness. But what happened?
Since Sue was so young, and in otherwise good health, her family agrees to an autopsy. But the procedure yields a completely unexpected outcome. Whilst conducting the autopsy, the assistant medical examiner notices a strange scent coming from Sue’s body. It is a scent similar to that of bitter almonds. And the examiner recognises it immediately: this is not the smell of almonds at all, but the smell of cyanide. A rapidly-acting and deadly-poisonous chemical. Susan Snow has been murdered.
When Sue’s movements on that fateful June 11th morning are retraced, the police investigating her death are led back to one vital element. Those painkillers she took before getting into the shower to treat her headache. They were a drug called Excedrin, a seemingly innocuous mix of aspirin and paracetamol commonly marketed for headaches. But the bottle Sue had in her house was not so innocuous at all, and as well as aspirin and paracetamol, this particular bottle also contained cyanide.
The store from which Sue purchased her Excedrin tablets is subsequently investigated, and more contaminated drugs are found, also tainted with cyanide. A total of three separate bottles containing cyanide are discovered, and police begin to worry that this is only the tip of the iceberg. Their fears seem to be confirmed when someone new comes forward claiming their partner may have been poisoned by the tainted Excedrin, too. This person is 42 year-old Stella Nickell, a recent widow who alleges that her husband Bruce had died in mysterious circumstances, also after taking Excedrin to treat a headache.
On 5th June, just six days before the death of Susan Snow, Bruce Nickell, a heavy equipment operator, had returned from work complaining of a sore head. He took a couple of Excedrin tablets, hoping they would do the trick, but before he could even so much as sit down, he’d collapsed onto the floor. Stella, his wife of ten years, called for help and Bruce was, like Sue, airlifted to hospital. Also like Sue, Bruce died shortly after arrival. However, very unlike the case of Susan Snow, an autopsy on his body determined that Bruce had died from natural causes, and his cause of death was given as emphysema.
Bruce’s death seemed a little odd. He had recently cleaned up his life after years of alcohol abuse, quitting the substance altogether. He had also been given a medical by his employer before starting his new job, during which nothing was found to be wrong with him. Nevertheless, his wife Stella grudgingly accepted the coroner’s verdict, and the day after his death called Bruce’s place of work to inform them what had happened.
But when Stella Nickell hears about the death of Susan Snow from the tainted Excedrin tablets, she can’t help but come forward to volunteer information to the police about her husband’s death. She turns two bottles of Excedrin over to the authorities, bottles that she tells them she purchased two weeks apart from two separate locations. When the police look into these particular drugs, they discover the lot numbers of the bottles match the other tainted bottles, in particular the pills that led to the death of Susan Snow. As a result, the authorities decide to reopen the case of Bruce Nickell’s death, and take a sample of his blood. It tests positive for cyanide.
Two deaths in the space of a few days from poisoned tablets which potentially could have killed many more people force the authorities to turn their attention to the company that makes Excedrin. However, due to the drug’s strict production process, police conclude the manufacturer is not responsible and that, therefore, contamination must have taken place at store level. This rings alarm bells for the authorities. Only four years earlier in Chicago, a spate of pharmaceutical drug tamperings in which bottles of Tylenol had been laced with potassium cyanide had left seven people dead. It had also given rise to significant changes in product packaging, with more stringent anti-tampering packaging and laws being introduced, and more CCTV being installed inside of stores. However, nobody had ever been arrested for carrying out the ‘Tylenol Murders’, as they came to be known. Could the same perpetrator still be operating, moving west from Chicago to take up residence in Washington State? Or could the Excedrin poisonings be the work of some kind of copycat?
The FBI undertakes a thorough examination of the contaminated tablets recovered from Susan Snow, Stella Nickell and the women’s local drugstores. And they are amazed to discover something other than cyanide contaminating the Excedrin tablets in question. It is a substance they could never have predicted finding: green flecks… crystals which, when analysed, are found to have come from an algaecide with the brand name Algae Destroyer, used to kill off algae in pet fish tanks and aquariums across the country. But why would a potential poisoner have any need to add such a chemical to the tainted drugs, in addition to the extremely deadly cyanide? And, furthermore, who could have put it there?
The Method
As well as the lethal substance cyanide being found in several contaminated bottles of the painkillers Excedrin, the FBI also identifies algaecide in the drugs as well; specifically Algae Destroyer, a chemical more commonly used in the maintenance of fish tanks. And it doesn’t take them long to notice that there is one person associated with the case who has a large fish tank prominently displayed in their home. That person is Stella Nickell. But could Stella really be behind these crimes; a woman who had voluntarily come forward claiming her own husband had met his death at the hands of the Excedrin poisoner?
The FBI sets about trying to link Stella directly to the contaminated Excedrin. They ask around local pet shops in an attempt to determine whether she had recently been in to buy algaecide. In one shop, they strike gold. A shop assistant says yes, there is a woman who comes in regularly to purchase the exact brand of algaecide found in the contaminated pills. That he remembers her especially as she always has a bell jangling from her handbag, a handbag very like one Stella Nickell is known to own. He also states that instead of buying the liquid version of Algae Destroyer, Stella prefers the tablets, so the shop assistant had given her particular instructions to crush them up before adding them to her aquarium.
Following this information, the FBI digs a little deeper into Stella Nickell. They think it strange that, out of the five tainted bottles of Excedrin that they know of, Stella had apparently bought two. Moreover, she claimed to have bought them from two different shops, two weeks apart. It was either an instance of extraordinary bad luck, or else too much of a coincidence. The odds just didn’t add up.
The FBI also discovers that Stella had recently taken out a series of life insurance policies and, when they examine Bruce’s signature on these policies, they deduce that it has been forged. And that the handwriting matches Stella’s. Furthermore, her bank manager reveals that Stella had been in debt but that, in a recent letter to him, she had stated that her financial situation was about to be resolved, and that Bruce would no longer be involved.
Bruce’s employer is another person the FBI interviews to try and uncover more evidence as to Stella’s guilt. He tells investigators that when Stella rang him up the day after Bruce’s death, her manner on the phone had been bizarre given her husband had died so suddenly the previous day. In addition, when the authorities request Stella Nickell undergoes a polygraph test, she refuses. And yet none of this evidence is concrete enough to conclusively prove that Stella had indeed been the mastermind behind the contaminated Excedrin. The FBI needs more.
The information they’ve been waiting for emerges the following year, courtesy of a very surprising source. Cynthia Hamilton, known as Cindy, is Stella’s oldest daughter, and she comes forward to furnish the FBI with a set of damning claims about her mother. The first thing Cindy says is that her mother had grown bored of Bruce, and had been looking for a way to get him out of her life for some time, even unsuccessfully attempting to poison him on a number of previous occasions. During these times, he fell ill but recovered, assuming he had stomach flu. Cindy then states that Stella had made a succession of trips to her local library, with the express intention of researching methods of poisoning. When the FBI visits the library to verify this claim, they discover eighty-four fingerprints belonging to Stella in a collection of books about poisonings, fingerprints that are particularly numerous on the pages relating to cyanide. Indeed, library borrowing records also show that Stella had recently taken out two books on poisoning entitled Deadly Harvest and Human Poisonings from Native and Cultivated Plants, and that the latter of these had never been returned.
Despite Cindy’s seemingly damning account of her mother, Stella maintains her innocence. She and Cindy had always had a somewhat troubled relationship, and Stella is adamant that Cindy is only making such claims about her in a bid to con her out of money, as well as reaping the reward money being offered for information about the case. She tells the FBI that Cindy is in debt and trying to write it off. Stella claims she was never bored of Bruce, never tried to poison him, never contaminated the bottles of Excedrin and flat-out contradicts everything Cindy has said.
When Stella is eventually charged and the case goes to trial, her defence team alleges that her interest in books about poisons merely stemmed from a bid to keep her grandchildren safe when they were playing outside near potentially toxic plants. They also allege that her fingerprints on all those library books were made after Bruce’s death when, disbelieving his official cause of death, she’d been curious as to how her husband might have died, causing her to conduct her own research into various poisons.
What her defence team don’t try to explain away is the fact that the same brand of algaecide Stella is known to buy is present in the contaminated bottles of Excedrin. It is determined that Stella used the same container to mix the cyanide with the headache pills that she used to crush up her Algae Destroyer tablets before adding them to her fishtank.
So, what was Stella’s motive for killing her husband? Was it boredom, money… or both?
Stella’s co-workers told police that, in the months leading up to her husband’s death, she had become painfully bored with her life. That Bruce’s decision to give up alcohol had apparently led to the fun being sucked out of her own life, too. Moreover, she had been in debt and needed the cash. In addition to Bruce’s life insurance money, she’d had an eye firmly on any extra cash that could be made from successfully suing the manufacturers of Excedrin. Her actions had been inspired by the Tylenol Murders in Chicago, and she thought that, just like the perpetrator in that case, there was every chance she would get away without being caught, too.
And what of her decision to come forward and cause the FBI to reopen the case into Bruce’s death? It had, after all, already been ruled unsuspicious. As far as the wider world was concerned, Bruce had died of emphysema and had already been buried. Stella’s choice to poke her head above the parapet and be the one to inform the FBI that her husband’s death – a death she had been responsible for – was dubious, was also motivated by money. If Bruce’s death could be proven to be accidental, then Stella stood to gain an additional $100K life insurance payout. The last piece of the puzzle fell into place and it was revealed that when Bruce’s death had been ruled a result of natural causes and not an accident, Stella had planted contaminated Excedrin on the shelves of local stores. Her desire to secure an extra $100K by incriminating the manufacturers of Excedrin as selling contaminated tablets – and, therefore, proving that Bruce’s death was accidental – led to the death of an innocent woman and left Susan Snow’s children without a mother. It was only fortunate that more people didn’t pick up the other bottles of pills Stella had laced with cyanide and meet their ends in the same way.
Ironically, at the time of the murders Stella Nickell had been working as an security screener at Seattle-Tacoma International airport, responsible for checking that items passing through the airport didn’t pose a danger to passengers or staff. She was subsequently found guilty of five counts of product tampering and sentenced to ninety years in prison, where she remains to this day.
© 2025, Lora Jones. All rights reserved. Reproduction prohibited without written permission.
