Lizzie Borden took an ax

And gave her father forty whacks

And when she saw what she had done

She gave her mother forty-one.

In fact, when she came downstairs on the morning of August 4, 1892, Lizzie Andrew Borden gave her father Andrew Jackson Borden only ten or eleven whacks, and her stepmother Abby Durfee Gray Borden twenty. Nearly a century and a quarter later, criminologists, historians, and true crime buffs are still arguing as to the how and why — and even the who — of the thirty-one whacks that broke the silence of the Borden household that summer morning. Theories have been advanced claiming that the maid did it, that Lizzie Borden was a depraved lesbian of the sort pulpy crime novels thrive on, or that an illegitimate son emerged from obscurity to butcher Andrew Borden and his wife. Despite the wealth of theories, no consensus has emerged as to who committed the grisly crime. In fact, the only thing that is sure in the Borden case is that somebody — whether Lizzie Borden or another — got away with murder. Brought to trial in 1892, Borden was acquitted of the crime and spent the rest of her life living with her sister in the same town where their parents had died.

In 1976, Emily Toth, Janice Delaney, and Mary Jane Lupton advanced another theory of the officially unsolved Borden murder in their groundbreaking book The Curse. Unlike many of the other books which had already spun plausible versions of the Borden crime, The Curse was not, in fact, a book about Lizzie Borden, or even about murder more broadly. Subtitled A Cultural History of Menstruation, the book provided the first comprehensive analysis of the experience and meaning of menstruation across history, with examples from fiction, art, and advertising. At the back of the book, the authors included a “Menstrual Hall of Fame” listing admirable, or at least notable, menstruators from history and literature. Last on the list, somewhat incongruously, was Lizzie Borden.

Lizzie, according to the authors, was no ordinary menstruator: she “had always been noted for ‘peculiar spells’” coinciding with her monthly cycle, spells identified by the authors as “epilepsy of the temporal lobe, or psychomotor epilepsy.” Based on this information, the authors of The Curse conclude that the murder of Andrew Borden and his wife resulted from a fatal accident of their daughter’s biology, when “her period coincided with an epileptic attack.”

Toth, Delaney, and Lupton’s theory of the crime is not unique: rumors of Lizzie’s epilepsy can be found elsewhere, and many have focused on the presence of bloody cloths in the Borden household on the day of the murder, as well as Borden’s testimony at trial that blood found on her dress was from “a flea bite” — contemporary code for a menstrual period. The agreement between the prosecution and the defense to set aside all evidence with menstrual associations speaks to the place of such topics in Victorian America, and, according to the authors of The Curse, allowed America’s “only menstrual murderess” to walk free.

It’s a compelling concept, particularly when rooted in the grim mystery of the Borden household — a woman driven mad by one of the body’s deepest mysteries, a bloody murder resulting from the violent malfunction of the reproductive system’s bloody monthly ritual. But to call Lizzie Borden the only menstrual murderess is to overlook a little-discussed criminal history that linked women’s reproductive functions to a particular form of insanity, which doctors, lawyers, and juries believed was responsible for a spate of murders throughout the postbellum period.

A better candidate for the title of “menstrual murderess” is a far less famous woman by the name of Mary Harris. Raised in a small Iowa town in the years leading up to the Civil War, Harris was acquainted at a young age with a government clerk named Adoniram J. Burroughs, who courted Harris from the time she was 12 before departing for a job in the Treasury Department in Washington, D.C. When the paper published the engagement announcement of Burroughs and another woman, Harris became distraught, behaving in an increasingly bizarre and distressed manner: she wept frequently, tore her clothes, and slept on the floor despite friends’ entreaties to go to bed. Finally, in the summer of 1865, Mary Harris traveled to Washington, waited in the hallway of the Treasury building, and shot Adoniram Burroughs twice in the back as he left work for the day.

Surely, this was a cut-and-dried case if ever there was one: witnesses could testify to the crime, and Harris herself made no effort to deny that she had shot Burroughs. Yet Harris was judged not guilty by a jury of her peers and never served so much as a night in prison for the murder of A. J. Burroughs.

The evidence responsible for this verdict came from the testimony of six physicians, who gave evidence at Harris’s trial of the defendant’s history of dysmenorrhea, or painful menstruation, and its possible effect on her mental state. Harris, evidence showed, had been on her period at the time of the murder, and for many years prior had been seeing a Dr. Calvin M. Fitch in Chicago to address the undue pain she experienced during her “time of the month.” Testifying to this fact in Washington, Dr. Fitch added that “uterine irritability is one of the most frequent causes of insanity,” including what he called “paroxysmal,” or temporary insanity. One after another, Dr. Charles H. Nichols, Dr. John Frederick May, Dr. Thomas Miller, Dr. William P. Johnston, Dr. Flodoardo Howard, and prison physician Dr. Noble Young agreed with Fitch’s testimony: irritation of the uterus, particularly in combination with significant emotional distress, was sufficient to produce temporary insanity, which would render the sufferer blameless for her actions. Evidently, the squeamishness that would not admit the bloody evidence at Lizzie Borden’s trial did not trouble the war-torn nation in 1865. Mary Harris walked free.

Mary Harris’s trial would be a curious artifact of medical history — if it had been an isolated incident. In fact, the Harris case became the precedent for a developing theory of female crime. Later in the century, the trials of Fanny Hyde, Josephine McCarty, and other women accused of violent crimes showed that juries could be swayed by medical evidence suggesting that uterine excitement could equate to mental derangement, resulting in a moment of insanity during which the worst could happen without the woman’s conscious intent. And today, the question lingers: might women’s unique physiology sometimes account for uniquely violent or irresponsible behavior? In 1991, the Baltimore Sun reported “America’s first successful criminal defense based on premenstrual syndrome” when a Virginia surgeon was acquitted on drunk driving charges based on medical evidence that PMS had affected her behavior.

What we don’t fully understand, we treat with caution, and for fifty percent of the population, menstruation is a big, bloody question mark. It’s the mystery of menstruation, as much as the blood and the mental upheaval, that linked it to murder and madness since long before Lizzie Borden picked up her ax. In 1865, when the field of modern gynecology was in its earliest infancy, the cloud of mystery surrounding Mary Harris’s condition was impenetrable — and understandable. But the superstition of the menstrual murderess still lingers over a century later, encouraged by inadequate sex education and the stubborn ignorance of misogyny. By shying away from the topic in public spaces and ignoring the history of menstruation in the courtroom, we allow the misconception that Lizzie Borden or Mary Harris represent something unusual or unprecedented, rather than recognizable cases of the same troubled accusation that’s been leveled against the uterus over the centuries.