BOSTON — A federal jury on Tuesday convicted former Stoughton, Massachusetts, police detective Matthew Farwell of murdering 23-year-old Sandra Birchmore and causing the death of her unborn child, capping a federal trial that exposed a botched initial local investigation into what was first ruled a suicide.
Farwell, who news reports described as either 40 or 41 years old, was found guilty in federal court in South Boston of killing a witness or victim and causing the death of an unborn child. The convictions carry a mandatory sentence of life in prison without parole, according to CBS News and ABC News. Sentencing was set for Feb. 3, 2027.
The jury of eight men and four women deliberated for about 14 hours over two days, according to the New York Post. Jurors had notified the court on Monday afternoon that they were deadlocked, but they resumed discussions Tuesday after the judge directed them to keep working.
Years of Grooming and a Staged Crime Scene
Birchmore was discovered dead inside her Canton apartment on Feb. 1, 2021, with a strap wrapped around her neck. Massachusetts State Police investigators and the state medical examiner initially classified the death as a suicide. Following an FBI inquiry launched two years later, federal authorities arrested Farwell in 2024, and the medical examiner altered Birchmore’s official manner of death to “undetermined.”
Prosecutors established that Farwell first encountered Birchmore through a youth explorer program run by the Stoughton Police Department, when she was 12 or 13. By the time Birchmore was 15 and Farwell was 27, he had initiated an illegal sexual relationship with her, prosecutors told jurors. Under Massachusetts law, the age of consent is 16.
Birchmore became pregnant in late 2020 with a boy, and both she and Farwell believed he was the father, though later DNA testing determined another man was the biological parent, ABC News reported. Federal prosecutors said Farwell strangled Birchmore to prevent her from reporting his statutory abuse, just days after a tipster alerted the Stoughton department about their illicit connection and the day before Farwell’s wife gave birth to their third child.
“Today, justice was served for Ms. Sandra Birchmore and her unborn son, both of whom died at the hands of Matthew Farwell,” U.S. Attorney for Massachusetts Leah Foley said at a press conference, calling his actions “absolutely diabolical behavior.”
Clashing Expert Testimony and Flawed Police Probe
The government presented about 50 witnesses and 500 exhibits during the nearly monthlong trial, ABC News reported. Investigators recovered approximately 40,000 text messages between Farwell and Birchmore. Prosecutors also presented digital forensics showing Birchmore’s cellphone ceased moving three minutes prior to building surveillance cameras filming Farwell exiting the premises.
A prosecution medical expert, Dr. William Smock, testified Birchmore suffered injuries demonstrating that she struggled while being strangled by a duffel bag strap. Conversely, defense expert Dr. Thomas Andrew, a former New Hampshire chief medical examiner, contested the finding of homicide.
Defense attorney Kimberly Stevens told jurors Birchmore had long struggled with mental health issues and took her own life after Farwell arrived to end the relationship. Farwell’s attorneys acknowledged the affair occurred but claimed it began when Birchmore was 16 and legal to consent.
Federal prosecutors openly condemned the original state-level inquiry, telling jurors detectives conducted a hurried 15-minute parking lot interview with Farwell without taking notes, checking him for scratches, or collecting his DNA. Norfolk District Attorney Michael Morrissey issued a statement defending his office, saying state prosecutors were constrained by the medical examiner’s initial suicide ruling, though they later referred the case and supported federal prosecutors.
Birchmore’s cousin, Barbara Wright, told reporters outside court that the family had waited nearly six years for accountability. Farwell remains detained in federal custody pending his February sentencing hearing.
