Hannah Ocuish was born in March 1774 in Groton, Connecticut, to a Pequot mother. Orphaned at a young age, she was placed in various foster homes and was believed to have an intellectual disability. By 1786, at the age of 12, Hannah was living as an indentured servant to a widow named Mrs. Rogers, residing approximately three miles from New London. Her early life was marked by instability and hardship, reflective of the limited support systems available for children of her background during that era. ​

On July 21, 1786, six-year-old Eunice Bolles, daughter of a prominent New London farmer, was found murdered along the Norwich Road. Her body exhibited severe injuries, including a fractured skull and signs of strangulation, with heavy stones placed upon her body, seemingly to suggest an accidental death caused by a collapsed stone wall. ​

The following day, Hannah Ocuish was questioned by authorities. Initially, she claimed to have seen four boys near the scene, but when these individuals could not be located, suspicions turned toward her. Under further interrogation, Hannah allegedly confessed to the murder, stating that she had lured Eunice with the promise of a gift, then attacked and killed her as retribution for Eunice having reported her for stealing strawberries weeks earlier. ​

Hannah was arrested and indicted for murder. Despite her age and apparent intellectual challenges, she was tried as an adult, as juvenile considerations were not recognized in the legal system of 18th-century America. During her trial in October 1786, she pleaded not guilty but was ultimately convicted. The presiding judge, Richard Law, acknowledged her youth but stated that sparing her due to age would be detrimental, implying that leniency could encourage other children to commit severe crimes without fear of significant consequences. Consequently, Hannah was sentenced to death. ​

On December 20, 1786, after a sermon delivered by Reverend Henry Channing emphasizing parental and societal duties, Hannah Ocuish was publicly hanged behind the New London meetinghouse. Witnesses reported that she appeared greatly afraid and seemed to seek assistance as she approached the gallows. At 12 years and 9 months old, she remains the youngest person known to have been legally executed in the United States. ​

In recent years, Hannah's conviction and execution have been subjects of scrutiny, with questions raised about the validity of her confession, the fairness of her trial, and the influence of racial and social biases on her treatment by the justice system. ​