'Monster: The Lizzie Borden Story' Ending Explained: What's True in the Series?

Warning: This text contains spoilers for Monster: The Lizzie Borden Story.

The fourth season of Monster starts with a different challenge than previous stories in Ryan Murphy and Ian Brennan 's anthology. Unlike Jeffrey Dahmer and Ed Gein, Lizzie Borden was never convicted of the crimes that made her famous. Accused of killing her father, Andrew Borden, and her stepmother, Abby Borden, in 1892, she was acquitted the following year—and no one else was held accountable for the murders.

It is precisely in this space left by history that the Netflix series constructs its version of events. Without much concern for preserving the ambiguity of the case, Monster: The Lizzie Borden Story asserts that Lizzie was guilty, but adds a major twist: she did not act alone. In the production, the maid Bridget “Maggie” Sullivan is her lover, accomplice, and partner in both the murders and the cover-up of evidence.

Who killed Andrew and Abby in Monster?

In the series version, Lizzie and Maggie kill Andrew and Abby together. Before that, the production shows Lizzie murdering Bertha Manchester, a neighbor who mistreated her maid. The death serves as a rehearsal for the main crime and, at the same time, as the moment when Lizzie stops merely fantasizing about violence and decides to act.

The two women still try to poison Andrew and Abby by serving them spoiled oysters, but the couple survives. When the plan fails, Lizzie resorts to a much more direct method. She delivers the first blow to Abby in the guest room, while Maggie initiates the attack on Andrew, who is later found on the sofa. Lizzie participates in both murders, making it clear that she is not only the mastermind behind the plan but also its main executor.

The motive brings together several elements presented throughout the season: the dispute over the inheritance, the repression imposed on women during that period, the suffocating relationship with her father and stepmother, and the death of Lizzie's birds. Maggie also sees crime as an escape from her submissive position and the abuse she faces working in the house.

After the murders, the two burn their bloodstained clothes and construct their alibis. It's a rather assertive choice by the series, which prefers to transform the mystery into a crime novel rather than continue debating whether Lizzie was guilty or not. More than reconstructing the case, Monster uses the murders to talk about two women who see violence as an extreme—and evidently monstrous—form of liberation.

How does Lizzie manage to get acquitted?

Although the investigation eventually leads to Lizzie, the police don't find enough physical evidence to definitively link her to the murders. The series also explores one of the most important elements of the real case: the difficulty society at that time had in believing that a white, religious woman from a respected family could commit such a brutal crime.

Lizzie understands this perception and learns to use it to her advantage. In the plot, Nance O'Neil helps her approach the trial as a great performance. Instead of trying to convince the jury solely through facts, she constructs the image of a fragile, traumatized woman, incapable of wielding a hatchet against her own parents.

The strategy works. While the prosecution relies on circumstantial evidence, contradictory testimonies, and a weapon that cannot be conclusively linked to the deaths, the defense transforms Lizzie's own femininity into an argument. She is acquitted and free to receive her father's inheritance.

However, acquittal does not mean acceptance. Lizzie achieves the legal and financial freedom she desired, but remains imprisoned by her own reputation. The society that failed to convict her also never ceases to treat her as a murderer.

In real life, the outcome was similar. Lizzie was acquitted in June 1893 by an all-male jury after about 90 minutes of deliberation. There was no blood on her clothes, the murder weapon was never definitively identified, and some of the evidence against her was excluded from the trial. The case officially remains unsolved.

What happens to Lizzie after the trial?

After being acquitted, Lizzie and Emma buy a mansion in an upscale area of ​​Fall River. The house, called Maplecroft, represents everything their father had denied his daughters: independence, comfort, and a position in the wealthiest part of town. But the move doesn't erase the past.

Lizzie and Emma eventually break off their relationship, leaving the protagonist alone with her inheritance and the burden of fame. This also has a basis in reality. The sisters lived together until 1905, when Emma left Maplecroft after a series of disagreements. One of the possible causes was Lizzie's friendship with the actress Nance O'Neil, as well as the parties held at the mansion. The two apparently never spoke again.

Lizzie remained in Fall River, adopted the name "Lizbeth," and died in 1927 at the age of 66. Emma died just nine days later. Even decades after her acquittal, however, Lizzie continued to be treated as guilty in the popular imagination—something the series itself reinforces by presenting her version of the crime as truth.

Why does Aileen Wuornos appear at the end?

The season finale jumps forward almost a century to return to Aileen Wuornos, played by Sarah Paulson. Convicted of murdering six men and executed in 2002, she is presented as a sort of heir to the Lizzie Borden legend.

In her final moments, Aileen has a vision of Lizzie and Maggie calling to her. This isn't a literal supernatural connection, but rather the conclusion of the thesis the season attempts to build upon: women transformed into "monsters" by violence, abuse, and the way their crimes are consumed by the public.

The comparison is provocative, although it simplifies two very different stories. Lizzie was acquitted and lived to old age; Aileen was convicted and executed. One became a historical mystery, while the other had proven crimes. For Monster , however, both belong to the same lineage of women whose violence defies social expectations and, therefore, takes on an almost mythological dimension.

The final scene also revisits the anthology's main question: are monsters born that way, or are they created by circumstances? The series is clearly more interested in the latter possibility, even if it never completely absolves its characters of responsibility for their choices.

What is true and what was invented by the series?

The central point of the story is true. Andrew and Abby Borden were murdered inside their home on August 4, 1892. Abby died first, upstairs, and Andrew was attacked about an hour and a half later while on the sofa. Lizzie and Bridget were on the property during the time the crimes occurred.

Lizzie also gave conflicting accounts of her whereabouts, attempted to purchase prussic acid shortly before the deaths, and burned a dress a few days later. A hatchet without a handle was found in the basement, but none of this evidence proved her guilt. There was no blood on the clothes she was wearing when the bodies were found, and the alleged weapon was never definitively linked to the injuries.

As for the romantic relationship with Maggie, it belongs to the realm of speculation. Bridget Sullivan existed, worked for the Bordens, and was in the house on the day of the murders, but she was never accused of involvement. There is no proof that she and Lizzie were lovers or planned the crimes together. The series transforms a popular theory about Lizzie's sexuality into a fundamental piece of its narrative.

Nance O'Neil's involvement in the trial is also fabricated. Lizzie only met the actress after being acquitted. The two became close, but Nance did not prepare her for the trial and had no known involvement in her defense.

The family's birds were indeed killed by Andrew, although, according to Lizzie's testimony, he wrung their necks because he believed they attracted children to the property. There is no evidence that they were animals she particularly loved or that the episode provoked any desire for revenge. The deliberate attempt to poison them with oysters and the murder of Bertha Manchester are also creations of the production.

Ultimately, Monster: The Lizzie Borden Story uses historical records as a framework, but it doesn't intend to function as an impartial investigation. Ryan Murphy and Ian Brennan choose the most dramatic, romantic, and bloody version available: Lizzie killed, Maggie helped, and the two made the crime a way to escape the world that imprisoned them.

It's a coherent interpretation of the season's themes, but not a historical conclusion. More than 130 years later, we still don't know who killed Andrew and Abby Borden. Netflix offers a rather self-assured answer—but the true fascination of the case remains precisely in the fact that we may never have one.