Sandra Birchmore

Case background and investigation

Sandra Birchmore joined the Stoughton Police Explorers, a youth program run by the Stoughton, Massachusetts, police department, in 2010 at age 12. There she met Matthew Farwell, who was hired by the department in 2012 and volunteered with the program. Federal prosecutors allege that Farwell began a sexual relationship with her in 2013, when she was 15 and he was 27, and that some encounters took place while he was on duty.

In December 2020 Birchmore learned she was pregnant and told Farwell she believed he was the father. On January 20, 2021, a friend of hers called the Stoughton police department to report the relationship. On February 1, 2021, during a snowstorm, surveillance video showed Farwell entering her apartment building in Canton in the evening and leaving about half an hour later. On February 4, 2021, after she missed several days of work at the Sharon public schools, Canton police conducted a well-being check and found her dead. In May 2021 a state pathologist ruled the death a suicide by hanging.

Farwell resigned from the department on April 1, 2022. In September 2022 Stoughton police released the results of an internal investigation that found inappropriate relationships between Birchmore and three officers, including Farwell and his twin brother William; the officers denied the accusations. Her estate filed a wrongful death lawsuit in December 2022 against the Farwells, a supervisor and the town. Federal investigators then re-examined the death, and a former New York City chief medical examiner retained by investigators concluded it was a homicide.

On August 28, 2024, a federal grand jury indicted Farwell on a charge of killing a witness or victim, alleging that he strangled Birchmore and staged her apartment to look like a suicide in order to prevent her from reporting his sexual abuse of a minor. He pleaded not guilty. A DNA test in 2025 showed he was not the father of her unborn child. On October 28, 2025, a superseding indictment added a count of causing the death of an unborn child; the indictment stated she was eight to ten weeks pregnant. In December 2025 prosecutors said they would not seek the death penalty. The killing-a-witness count carries a mandatory life sentence if he is convicted.

Farwell's trial opened before Chief U.S. District Judge Denise J. Casper at the Moakley Courthouse in Boston, with jury selection on October 6, 2026, and opening statements on October 9, 2026. Prosecutors told jurors Farwell killed her to keep the relationship hidden; his lawyers conceded a relationship but said Birchmore, who was struggling, died by suicide after he ended it. Witnesses in the first week included Stoughton police officials, a friend of Birchmore's and FBI forensic examiners who testified about tens of thousands of messages recovered from her devices. The trial was expected to last about five weeks. Farwell is presumed innocent unless convicted.