Elizabeth Jeffries was born in 1727 in Bridgnorth, Shropshire, England. At the age of five, she was adopted by her wealthy and childless uncle, Joseph Jeffries, a successful London butcher who had amassed considerable wealth in the capital. While this adoption may have seemed a generous act, it later turned sinister when Joseph sexually abused Elizabeth at the age of fifteen—a fact that shaped the toxic and ultimately deadly dynamic between them.

Despite promising her his fortune in his will, Joseph Jeffries frequently threatened to disinherit his niece, often using accusations of immorality and misconduct against her. His controlling behavior and the imbalance of power in their relationship created mounting pressure on Elizabeth, especially as she reached adulthood. By the time she was in her early twenties, Elizabeth had grown resentful of her uncle’s erratic generosity and psychological torment.

During this period, she began a romantic and sexual relationship with John Swan, her uncle's manservant. The affair was clandestine but emotionally charged, and it grew deeper as the two found themselves united in dissatisfaction with their lives under Joseph’s household. As the threat of disinheritance became more real, and with Joseph continuing to wield his financial power over Elizabeth, she and Swan began to consider a more radical solution to secure her inheritance.

On the night of 3 July 1751, Elizabeth Jeffries and John Swan carried out a premeditated plot to murder Joseph Jeffries in order to gain access to his fortune. The two conspirators acquired a brace of pistols through an intermediary named Matthews, who became a critical witness later in the investigation. Though Matthews was aware of their plan and witnessed the couple in the house on the night of the murder, he claimed that Swan swore him to secrecy.

Jeffries and Swan went upstairs to Joseph’s room and shot him dead, staging the scene to appear like a botched robbery. They then raised the alarm, drawing suspicion away from themselves. Initially, Elizabeth was arrested, but due to lack of evidence, she was released. In an attempt to protect herself, she implicated Matthews, leading authorities to search for and interrogate him. Upon being located, Matthews confessed everything he knew—including the fact that he had provided the weapons and that Elizabeth and Swan had plotted the murder.

Both Elizabeth and John Swan were rearrested and charged with murder. They were held in prison for eight months awaiting trial.

Their joint trial took place on 10 March 1752, where they were both swiftly convicted of murder, with Swan also being convicted of petty treason—a charge applied when a servant killed his master. The sentence was death by hanging.

On the morning of 28 March 1752, Elizabeth and John were brought to the gallows before a crowd of 7,000 spectators. Elizabeth, standing at just 5 feet 1 inch tall, rode to her execution seated atop her coffin in a cart, while Swan was drawn on a sledge, the traditional punishment for petty treason. Upon arrival at the gallows, Elizabeth had to stand on a chair atop the cart to reach the noose, while Swan stood on the cart bed. Neither of their legs were bound, and they were not blindfolded. Witnesses noted that they did not acknowledge each other.

As the hangman cracked his whip, the cart was pulled from beneath them. Swan died quickly, but Elizabeth struggled for over 15 minutes, her lighter weight causing a slow and agonizing death by strangulation. Her prolonged execution was witnessed with grim fascination by the massive crowd.

The execution of Elizabeth Jeffries became one of the most discussed criminal events of the Georgian period, not only for its brutality but for the psychological dimensions of the case: a young woman, abused by the guardian who adopted her, ultimately participating in his murder for both revenge and financial security. Her story has since appeared in ballads, crime histories, and legal debates surrounding the felony murder doctrine and capital punishment in 18th-century England.