Rebecca Smith (née Prior) was christened on 17 May 1807 in the Wiltshire village of Bratton. Born into a respectable family, her father, William Prior, was a prosperous yeoman farmer who passed away in 1830. Her mother, Sarah Prior, held a prominent role within the local Particular Baptist congregation, grounding Rebecca in a tight-knit religious community.

In May 1831, Rebecca married Philip Smith, an agricultural laborer—and reportedly a heavy drinker. The year 1832 saw the birth of their first child, Jane. The couple went on to have ten more children, but tragically, none survived past infancy.

In 1846, Rebecca inherited £100, a substantial sum at the time, upon her mother's death. She used it to relocate her family to nearby Westbury, hoping perhaps for a fresh start. However, Philip squandered this inheritance, plunging the family into hardship. Rebecca found herself doing back-breaking seasonal work—picking crops and tending vegetables.

Rebecca’s eleventh child, Richard, was born on 16 May 1849. Initially, he seemed healthy, but by 7 June, he became ill, and tragically died on 12 June. Though the local registrar, George Shorland, initially marked the cause of death as unknown, mounting rumor and suspicion prompted a formal inquest.

Richard’s body was exhumed on 22 June and subject to autopsy on 24 June—revealing traces of arsenic in his stomach. Neighbors reported that Rebecca had repeatedly tried to buy poison before and after Richard’s birth, ultimately succeeding in purchasing “white arsenic” on 7 June.

Further investigation revealed more horror: exhumations and inquests on 18 July found arsenic in the remains of two more of her children, Sarah and Edward. 

Rebecca stood trial at the Devizes Assize Court on 9 August 1849. Eighteen witnesses testified, detailing her suspicious behavior—her attempts to buy poison, and the contradictory statements she made about Richard’s illness. After just 30 minutes of deliberation, the jury found her guilty. Although they recommended mercy, the judge ignored it and sentenced her to death.

One week later, Rebecca made a chilling confession to the prison chaplain: she admitted using rat poison to kill seven of her other children. In total, only her eldest, Jane, survived to adulthood; two perished from natural causes, and eight were murdered. She described her extreme fear that poverty would leave her children destitute, coupled with a husband whose alcoholism left the family vulnerable.

Despite two petitions for clemency sent to Home Secretary George Grey, the public and press largely supported her execution. She was publicly hanged at Devizes on 23 August 1849, making her the last British woman executed for infanticide.