Former Detective Convicted After 40,000 Texts Reveal Years-Long Relationship

Matthew Farwell, a former detective with the Stoughton Police Department, was found guilty on Tuesday of murdering Sandra Birchmore. The federal jury also convicted him of causing the death of her unborn child. The verdict concludes a trial that spanned more than three weeks.

Prosecutors argued that Farwell killed Birchmore in February 2021 inside her apartment in Canton. They stated that the motive was her pregnancy. Farwell and Birchmore had been in a relationship for several years, which began when she was 15 and he was 27.

Federal investigators analyzed approximately 40,000 text messages between the two. This digital record helped establish the history of their interactions. The evidence supported the claim that Birchmore threatened to reveal the relationship to the public.

Birchmore was initially found with a strap around her neck. Authorities first ruled the death a suicide. The medical examiner later changed the manner of death to undetermined. This shift prompted federal investigators to reopen the case.

The defense team maintained that Birchmore took her own life. They pointed to her documented mental health history and previous statements about ending her life. A medical expert hired by the defense disputed the prosecution's conclusion that she was strangled.

Jurors began deliberations on Friday. They sent a note to the judge on Monday stating they were deadlocked. The judge dismissed the jury for the day. They resumed deliberations on Tuesday and returned the final verdict.

Farwell faces a mandatory sentence of life imprisonment without the possibility of parole. The U.S. Attorney for Massachusetts confirmed the guilty verdicts on both counts.