There have been many female murderers over the centuries called a “Borgia,” in reference to Lucrezia Borgia, the Italian Renaissance-era noblewoman who, as stories claim, poisoned her husbands and lovers once they were no longer useful to her.
Maine had its own Borgia, a Penobscot County woman who over the course of a decade in the 1880s and 1890s allegedly fatally poisoned six members of her own family. Though it is possible others existed before her, she was likely Maine’s first — and certainly deadliest — serial killer.
Mary Knights Cowan was born in 1863 in the town of Plymouth, about 25 miles outside of Bangor. When she was 17 years old, she married Willis Bean of nearby Dixmont, with whom she had three children, Grace, Alice and Mabel. Bean wanted to attend medical school in order to become a physician, but with little money, the family could not afford to send him.
One by one, however, their children began to mysteriously die. Grace, who was around three years old at the time, died in 1884, of seemingly unknown causes. That same year, Alice died from a “peculiar” stomach ache, with Mabel succumbing to the same stomach problems in 1885.
The couple then convinced Bean’s parents to buy a farm for them to live in, for which they had a handshake agreement that they’d pay Bean’s parents back. The couple then left to go to Ohio, where Bean was set to study medicine. In 1888, however, Bean also fell ill with strange stomach pains and died.
According to an 1899 newspaper article detailing Cowan’s story, upon returning to Dixmont in 1890, Mary claimed the agreement to pay back Bean’s parents never occurred, and she sold the farm for $2,000 — about $66,000 in 2024 dollars.
Cowan quickly remarried a man named George Taylor, and less than a year later, Taylor died from — once again — strange stomach pains. Friends of Taylor’s in his local Odd Fellows lodge raised several hundred dollars to help the supposedly grieving widow.
In 1891, Cowan married one more time, to Elias Cowan, who had an eight-year-old son named Willis. In September 1894, both Elias and Willis came down with — you guessed it — severe stomach pains, with Willis dying a few days later, but Elias surviving. Newspaper articles at the time claimed Cowan’s motive was to inherit property directly from her husband, and not have it pass first to his son.
This time, however, police finally noticed that after ten years and six deaths involving horrible stomach pains and the husbands and children of Mary Cowan, maybe something wasn’t quite right here.
In early 1895, police sent Willis Cowan’s remains to Bowdoin College for an autopsy, which showed that the boy’s body tested positive for arsenic. One newspaper said it was “enough to kill an ox.” The most common symptoms of arsenic poisoning are severe abdominal pain, vomiting and diarrhea — exactly what Mary Cowan’s other alleged victims experienced before they died.
Cowan was arrested and charged with murder. The February 1895 trial in Bangor was a scandalous affair, with Maine newspapers covering each twist and turn. The story reached publications as far west as California, with reporters dubbing Cowan the “Borgia of Maine.” The trial lasted nearly a month, and though Cowan proclaimed her innocence throughout the proceedings, on March 2, 1895, a jury found her guilty of murdering her stepson.
Cowan was never tried for the five other deaths she was associated with — three of her own children and two husbands — but she was sentenced to life imprisonment for the murder of Willis Bean.
She spent the rest of her life in the Maine State Prison in Thomaston, where a few months into her sentence she gave birth to a daughter by Elias Cowan, the man she’d allegedly tried to kill the year earlier. The infant died shortly after birth, and Mary Cowan herself died in prison in September 1898. She is buried in Sawyer Cemetery in Plymouth — the same cemetery where Willis Cowan is buried, along with all of her other alleged victims and, eventually, Elias, the husband she’d also allegedly tried to kill.
Cowan was one of many “Borgia” or “Black Widow” serial killers in the U.S. in the mid-to-late 19th century, which generally refers to women who poison their husbands, family members and others — usually with arsenic, though other poisons and drugs were also used.
Some other well-known female murderers of the era who used poison include Sarah Jane Robinson, the “Boston Borgia,” who between 1881 and 1886 poisoned her husband, children, other family members and her landlord — eight victims in total.
Also in Massachusetts, Jane “Jolly Jane” Toppan, a Boston nurse, was one of the most prolific American serial killers of all time. She was convicted in 1902 of killing 12 family members, associates and patients between 1895 and 1901. She reportedly confessed to 31 killings in total, and police suspected she may have killed many more beyond that.
The story of Mary Cowan, Maine’s first and deadliest serial killer, is a gruesome chapter in Maine history — one that is largely forgotten, but was front page news when it happened more than 130 years ago.
