On March 30, 1928, the battered body of 27-year-old Marguerite Isabelle Stewart was found lying beside the Cambridge Turnpike in Concord, Massachusetts. A respected supervisor at the Beverly School for the Deaf and daughter of a Worcester family, Miss Stewart had suffered a massive, fatal blow to the skull. The right side of her head was caved in, her clothing was disheveled, and brain matter was found splattered on her coat. Her corsets were yanked down to her thighs, her bloomers half-removed, and bruises marked her wrists, knees, and under one eye—suggesting she was restrained, attacked, and beaten before death. At first, police believed she may have been the victim of a hit-and-run. But it soon became clear: this was murder, and a brutal one.
At the center of the case was Frederick Hinman Knowlton, Jr., a 34-year-old married father and proprietor of an electrical supply and battery business in Framingham. The son of a former selectman, Knowlton initially denied knowing the victim. But as police closed in, he admitted not only to knowing Stewart, but to having carried on a secret affair with her since she was a student at his father’s business school.
Miss Stewart, who was five months pregnant at the time of her death, had apparently been attempting to resolve the issue of paternity before her murder. Testimony later revealed she had confided in a probate registrar months earlier, alleging incestuous abuse by her brother and seeking help to enforce child support—a claim the court ultimately excluded from trial due to lack of corroborating evidence.
Investigators pieced together a damning chain of circumstantial evidence against Knowlton:
- A witness placed him arguing with a crying woman in his Chrysler roadster on the Concord-Framingham road the evening of March 30.
- Bloodstains were discovered in the vehicle, which Knowlton attempted to wash with chloride of lime the next day.
- A remote cabin in the Natick woods associated with Knowlton was found burned down shortly after the murder, in what authorities believed was an attempt to destroy evidence.
Knowlton was arrested on April 3, 1928, and arraigned in Concord District Court two days later. Despite pleas of innocence and the vocal support of his wife, who claimed he had been home the night of the murder, Knowlton was indicted for first-degree murder. His trial began in June 1928 and lasted just eight days. The prosecution, unable to prove premeditation or robbery, secured conviction on the grounds of “extreme atrocity or cruelty.”
Medical testimony underscored the heinousness of the crime. Dr. Walcott, the medical examiner, described a grisly scene: a large opening on the right side of the skull from which brain matter exuded, leaving that portion of the head nearly empty. Her coat was stained with blood and spattered with brain tissue. Her underclothes were disarrayed, with bloomers hanging from one leg and corsets dragged down. Red and yellow bruising marked her limbs. A scarf had been pulled tightly around her neck, and blood pooled beneath her eye. The violence was overwhelming.
Although Knowlton denied harming her, jurors concluded otherwise. On June 13, 1928, a Middlesex jury returned a verdict of guilty of first-degree murder. Knowlton showed no emotion as the foreman read the sentence: death by electric chair.
Knowlton’s legal team pursued appeals, arguing that the judge had erred in allowing the jury to consider “extreme atrocity” as a qualifying factor for first-degree murder. The Massachusetts Supreme Judicial Court unanimously upheld the conviction in December 1928, declaring that the physical violence and condition of the body fully justified the jury’s conclusion.
In the weeks leading up to his scheduled execution in May 1929, Knowlton’s wife and a new attorney mounted a final appeal to Governor Frank G. Allen, presenting letters of support and claims of newly discovered evidence. Among the claims were:
- A witness who allegedly saw Miss Stewart with another man shortly before her death.
- A challenge to juror impartiality, asserting that one juror had formed an opinion about the case before the trial began.
Both arguments were rejected. The sighting was deemed too vague and unsubstantiated, and the claim of juror bias lacked credible documentation. Governor Allen declined to intervene.
In the early hours of May 14, 1929, Frederick Hinman Knowlton, Jr., was led to the electric chair at Charlestown State Prison. Minutes earlier, he had been playing cribbage with a guard. He made no final statement. He left behind two letters: one to his wife Gladys, and one to his six-year-old son.
Thus ended the life of a man whose double existence—respectable businessman by day, secret lover by night—culminated in one of the most lurid and debated crimes in Massachusetts history. Marguerite Stewart, the devoted teacher whose life ended so violently, was buried in Worcester. Her name and tragic story would be forever entwined with the man from Framingham who took it all away.