The True Story Behind The Notorious Double Murder That Inspired Alias Grace

Here's the first thing you should know about Grace Marks (Sarah Gadon), the protagonist of Alias Grace, a new Netflix drama based on a Margaret Atwood novel of the same name: You probably shouldn't trust her. Yet, just like the young psychologist (Edward Holcroft) sent to examine her with his newfangled methods, you're likely to be swept away by Grace's storytelling skills. Is Grace lying, or isn't she?

Don't worry — we won't be delving into the question of Grace's reliability as a narrator, and consequently spoiling the whole fun of the show. Instead, let's look at the true events that inspired this compelling new show. With her 1996 novel Alias Grace, Margaret Atwood created a vivid account of one of Canada's most notorious crimes: the murder of wealthy Ontario-based landowner named Thomas Kinnear, and his housekeeper, Nancy Montgomery, in the year 1843.

The individuals ultimately convicted of the double murder? Kinnear's servants, 20-year-old James McDermott and — you guessed it — Grace Marks, who was only 16 at the time. That two young lovers could be accused of such a crime rendered this double murder the 1843 equivalent of the Menendez murders, or the Amanda Knox case.

Let's let Margaret Atwood, in her introduction to Alias Grace, describe just how riveting nineteenth-century Canadians found this murder.

"The details were sensational: Grace Marks was uncommonly pretty and also extremely young; Kinnear's housekeeper, Nancy Montgomery, had previously given birth to an illegitimate child and was Thomas Kinnear's mistress; at her autopsy she was found to be pregnant. Grace and her fellow servant James McDermott had run away to the United States together and were assumed by the press to be lovers. The combination of sex, violence, and the deplorable insubordination of the lower classes was most attractive to the journalists of the day."

Ultimately, Marks and McDermott were convicted of murder. McDermott was hanged, and Marks was sentenced for 30 years incarcerated, which she split between Kingston Prison and the Toronto Lunatic Asylum. Even after the trial, what remained unclear was Marks' true role in the crime. Was a naive, innocent Marks manipulated under McDermott's influence? Or could a 16-year-old girl really have instigated the double murder?

According to McDermott's trial statements, the answer is yes. “She told me if I would assist her, she would poison both the Housekeeper and Mr. Kinnear by mixing poison with porridge," McDermott said. Later, McDermott elaborated that, “Grace Marks is wrong in stating she had no hand in the murder; she was the means from beginning to end.”

We don't know much about Marks or her mental state at the time of the crime, though we do know she had a difficult life. One of nine children, Marks and her family crossed over from Ireland to Canada in the year 1840, only three years before the double murder took place. By the time Marks reached Canada, she was practically an orphan. Her father was a violent alcoholic, and her mother died at sea. The transition to her new home was challenging, too, as she arrived Canada at a time when Irish people and other immigrants were automatically ushered into a lower class of individuals.

Nothing in Marks' sparse biography explains why she would go so far as to kill her employers, so naturally, theories proliferated at the trial. Some thought Marks suffered from dissociative identity disorder. Others were less convinced by Marks' testimony, and thought she was play-acting mental illness in order to escape a more gruesome punishment. The final theory is a bit more outlandish. Marks' friend, Mary Whitney, had supposedly died some years earlier. There was thought that Whitney actually didn't die, but was impersonating Marks, who had died.

Either way, Marks went to prison for 30 years. She was eventually pardoned and released from prison in 1873. After that, the history books lose track of her.

Now, you're all set to watch Alias Grace, which will be released on November 3. Ultimately, what makes Alias Grace so fascinating aren't the details of the crime. It's Marks herself, never quite telling you what you want to hear.