A former Massachusetts police detective has been convicted of murdering a pregnant woman whom prosecutors said he had groomed since she was 15.
Matthew Farwell, once a detective with the Stoughton Police Department, was found guilty of killing Sandra Birchmore in her Canton apartment in February 2021. Investigators alleged that he arranged the scene to make the death look like a suicide.
The U.S. Attorney’s Office for Massachusetts said Tuesday that Farwell was convicted of murdering Birchmore and causing the death of her unborn child. The verdict came after jurors deliberated for several days following more than three weeks of testimony in federal court.
Jurors sent a note to the judge Monday saying they were deadlocked. The judge dismissed them for the day and ordered them to return Tuesday to resume deliberations.

Prosecutors say Sandra Birchmore was strangled inside her Canton apartment on Feb. 1, 2021, and that the scene was arranged to resemble a suicide. Former Stoughton police officer Matthew Farwell was convicted in her death. (Sandra Birchmore/Facebook, Stoughton PD, Getty)
Farwell was charged with killing a witness or victim and causing the death of an unborn child.
Prosecutors argued that Farwell killed Birchmore after she became pregnant and threatened to reveal their relationship. They said the relationship began after Farwell started grooming Birchmore when she was 15 and he was 27.

Sandra Birchmore shared this selfie on Facebook in January 2021, roughly three weeks before her death. Prosecutors alleged the scene was staged to look like a suicide and said former Stoughton police officer Matthew Farwell killed Birchmore and her unborn child. (Sandra Birchmore/Facebook)
Birchmore was discovered dead in her apartment with a strap around her neck. Authorities initially classified the death as a suicide, but a medical examiner later changed the official manner of death to undetermined.
Federal investigators later reopened the case. Their inquiry uncovered roughly 40,000 text messages exchanged between Birchmore and Farwell, along with evidence prosecutors said documented a sexual relationship lasting several years.

Matthew Farwell, a former Stoughton, Massachusetts, police officer, pleaded not guilty on Aug. 28, 2024, to charges that he killed a woman he was accused of sexually exploiting while she was underage. (Stoughton Police Department via AP)
In closing arguments, prosecutors depicted Farwell as a former police officer who feared Birchmore would expose his alleged misconduct.
Farwell’s defense countered that Birchmore died by suicide, citing her mental health history and earlier statements about suicide. His attorneys acknowledged the extramarital relationship but insisted he was not responsible for her death.
A medical expert for the defense also challenged the prosecution’s claim that Birchmore had been strangled.
Farwell faces a mandatory sentence of life in prison without the possibility of parole.