40,000 Messages Helped Convict Ex-Detective in 2021 Canton Homicide
Jurors found Matthew Farwell guilty of killing Sandra Birchmore and her unborn child after prosecutors presented digital evidence of a relationship that began when she was a teenager.
By Robert Ward ·
Matthew Farwell, a former detective with the Stoughton Police Department, was found guilty on Tuesday of murdering Sandra Birchmore and causing the death of her unborn child. The federal jury returned the verdict after three weeks of testimony in a trial that examined the circumstances surrounding Birchmore's death in a Canton apartment in February 2021. The conviction stems from federal charges that alleged Farwell killed a witness or victim and caused the death of an unborn child.
Prosecutors argued that Farwell killed Birchmore after she became pregnant and threatened to reveal a long-term sexual relationship. Evidence indicated the relationship began when Birchmore was 15 years old and Farwell was 27. The government presented approximately 40,000 text messages between the two to establish the timeline and nature of their interactions. Authorities stated that Farwell staged the scene to make the death appear like a suicide, a theory supported by the discovery of a strap around Birchmore's neck when she was found.
The initial ruling of death was suicide, but the medical examiner later changed the official manner of death to undetermined. Federal investigators reopened the case and gathered digital evidence that pointed to a yearslong sexual connection. During closing arguments, the prosecution portrayed Farwell as an officer who feared Birchmore would expose his alleged misconduct. The defense countered that Birchmore died by suicide, citing her history of mental health struggles and previous statements regarding suicidal ideation.
Farwell's attorneys acknowledged the extramarital relationship but maintained that he did not kill her. A defense medical expert disputed the prosecution's conclusion that Birchmore had been strangled. The jury sent a note to the judge on Monday indicating they were deadlocked. The judge sent the jurors home for the day and instructed them to return on Tuesday to continue their deliberations.
With the guilty verdict, Farwell faces mandatory life imprisonment without the possibility of parole. The case highlights the federal government's role in reviewing state-level homicide cases where the initial determination of death is later questioned. Birchmore's family and legal representatives are now preparing for the sentencing phase of the proceedings.
The trial took place in the U.S. Attorney's office for the District of Massachusetts. The jury's decision marks the end of the evidentiary phase of the federal murder trial. Farwell will remain in custody until sentencing.
