Boston
A former police detective was convicted Tuesday of killing a pregnant Massachusetts woman, Sandra Birchmore, to prevent her from revealing that he had sexually assaulted her when she was 15.
Matthew Farwell, 40, was convicted of strangling Birchmore on February 1, 2021, 12 days after an informant called the police department in the Boston suburb where he worked and reported they had had an inappropriate relationship. Birchmore, who was 23 when she died, had a tumultuous relationship with the detective, whom she first met while attending a Stoughton Police Department youth program as a child.
Prosecutors said Farwell staged the crime scene to make his death look like a suicide — and it almost worked. Massachusetts State Police investigators quickly concluded that Birchmore had committed suicide. But the FBI began investigating the case two years later and concluded it was a homicide.
Federal prosecutors harshly criticized the initial police investigation during Farwell’s trial, saying officers failed to follow up on leads and closed the case too quickly.
“Justice requires perseverance, not deference, not convenience, and certainly not protection for those who wear the badge and abuse their authority,” Ted Docks, the special agent in charge of the FBI’s Boston office, said at a news conference after the verdict. “No badge, no title, no position places anyone above the law.”
Birchmore’s cousin, Ray Cosgrove, said the family was grateful to those seeking answers, but stressed that no verdict could bring back Birchmore or her unborn son.
“Our family knew the person. The public knew the case,” Cosgrove said. “Sandra mattered before anyone outside of her family knew her name.”
Farwell’s lawyers acknowledged that the married detective had an affair with Birchmore, but said it began when she was 16, making her old enough to consent under Massachusetts law. They also maintained that he did not kill her. They argued that Birchmore had previously threatened suicide and that she killed herself after he went to her apartment to break up with her.
Farwell’s conviction carries a mandatory life sentence.
The trial, which lasted nearly a month — with about 50 witnesses and 500 exhibits — took place in a federal court in Boston, in part because local prosecutors never filed criminal charges.
Massachusetts State Police agents and investigators, some of whom had personal ties to Farwell, quickly concluded that Birchmore’s death was a suicide after she was found slumped on the floor of her apartment with a strap around her neck. An investigator, Assistant U.S. Attorney Brian Fogarty, told jurors he saw nothing suspicious in Birchmore’s apartment and concluded she was a “troubled girl who committed suicide.”
The state medical examiner, relying in part on information provided by police, initially ruled that Birchmore committed suicide. The office has since changed the official manner of death to “undetermined.”
The FBI began investigating Birchmore’s death in 2023, in part at the request of a former deputy chief of the Stoughton Police Department who had conducted an internal investigation into Farwell based on information the department received before Birchmore’s death.
Federal investigators concluded that the local investigation into his death was rushed and compromised. Farwell was questioned for just 15 minutes in a parking lot, they said. Investigators did not take notes, examine his injuries or take his DNA. Police only examined Farwell’s phone after he deleted the text messages with Birchmore.
The FBI investigation uncovered about 40,000 text messages between Farwell and Birchmore, including some in which they recalled having sex when he was 27 and she was 15 — too young to consent under Massachusetts law.
The texts also showed how contentious their relationship was becoming as Birchmore pressured Farwell to get her pregnant and threatened to tell his wife about their relationship.
Texts in late 2020, after her pregnancy, showed they argued over what role, if any, Farwell would play in the child’s life. A paternity test after Birchmore’s death revealed that another man was the father.
At trial, a digital forensics expert testified that Birchmore’s phone stopped moving three minutes before the lobby security camera recorded Farwell leaving his building the night of his death.
An expert hired by prosecutors, Dr. William Smock, said Birchmore’s injuries indicated she was strangled with the strap of a duffel bag and struggled before dying.
A defense expert, Dr. Thomas Andrew, New Hampshire’s former chief medical examiner, rejected Smock’s conclusion that it was a homicide.
Gn headline
