Five years ago, Sandra Birchmore was found dead in her apartment in Canton, Massachusetts. She was 23 years old and about eight weeks pregnant. The state medical examiner called it a suicide. Case closed. But this morning, in a federal courtroom in Boston, the prosecution is expected to start calling its first witnesses in the trial of the man it says actually killed her: Matthew Farwell, a former detective with the Stoughton Police Department who prosecutors allege groomed Birchmore from the time she was a teenager, then strangled her and staged the scene when she told him she was pregnant.
Farwell has pleaded not guilty. His defense team admits he carried on an affair with Birchmore but says he did not kill her. What comes next, over the next four to five weeks, is a case federal prosecutors have been building since September 2024, when a grand jury indicted Farwell on a charge of killing a witness or victim. A superseding indictment later added a second count tied to the death of Birchmore’s unborn child.
The girl who wanted to be a cop
Sandra Birchmore’s story starts with a dream. At 13, she enrolled in the Stoughton Police Explorer’s Program, a youth mentorship program for kids who wanted to go into law enforcement. That is where she met Matthew Farwell, a volunteer instructor and Stoughton police officer.
Prosecutors allege that Farwell used his authority and access to groom Birchmore for years, then began a sexual relationship with her when she was 15 and he was 27. According to an affidavit for detention obtained by PEOPLE, he “used his authority and access to groom, sexually exploit, and ultimately sexually abuse then-15-year-old Birchmore,” and prosecutors say the abuse continued after she became an adult.
Birchmore dreamed of becoming a police officer herself. Instead, prosecutors say, the man who was supposed to mentor her into the profession became the man who controlled and then allegedly ended her life.
What prosecutors say happened on February 1, 2021
The timeline the government has laid out to the jury is chilling in its detail. On February 1, 2021, prosecutors say Farwell ended the relationship, arrived at Birchmore’s apartment wearing a mask, strangled her, and staged the scene to look like a suicide. Prosecutors told jurors during opening statements on October 9 that she died just hours before Farwell’s own wife gave birth to their third child.
For three and a half years, the original finding stood. The Norfolk County District Attorney’s Office and the state medical examiner’s office concluded there were no signs of foul play. Then in September 2024, federal investigators reexamined the evidence, declared Birchmore’s death a homicide, and arrested Farwell.
The pregnancy at the center of it all
The prosecution’s motive theory hinges on the pregnancy. In October 2020, Birchmore reportedly learned Farwell’s wife was pregnant. Prosecutors told the jury she offered to keep their affair secret if he impregnated her. In December 2020, she told him she was pregnant, and prosecutors say he was angry and wanted “nothing to do with the baby.”
Birchmore, by contrast, was thrilled. A friend told PEOPLE in 2024 that she was “over the moon” about the pregnancy. Prosecutors said in opening statements that she told around 80 people about it. One wrinkle the defense is sure to lean on: subsequent DNA testing reportedly excluded Farwell as the biological father of the unborn child, a distinction that matters legally even though her belief at the time shaped the chronology.
The trial everyone is watching
Here is what we know about how the trial is unfolding at the John Joseph Moakley U.S. Courthouse in Boston (CBS Boston has day-by-day coverage):
- The jury: 16 jurors were seated on October 9, twelve plus four alternates, all residents of eastern Massachusetts. They have been told to avoid all media coverage of the case.
- The schedule: Testimony begins today, October 13, after opening statements on October 9. The case is expected to run four to five weeks.
- The star witness list: Among the names is Farwell’s twin brother, William Farwell, who previously admitted to having a sexual relationship with Birchmore, according to PEOPLE.
- The prosecution’s motion: On October 11, prosecutors filed a motion seeking to admit testimony about three alleged adult extramarital affairs, arguing Farwell made no effort to hide those relationships, in sharp contrast to his alleged behavior with Birchmore.
The defense’s counter is twofold. Farwell’s lawyers said in opening statements that he was “a flawed man” and admitted the affair, but they argued Birchmore died by suicide. They pointed to her mental health history and to forensic evidence, saying DNA found under her fingernails did not identify Farwell.
Prosecutors, for their part, have referenced a final text exchange between the two, apartment surveillance footage, alleged electronic communications, and forensic evidence. In post-opening arguments, lawyers clashed over the timing of Instagram data, the significance of Farwell wearing a mask, and DNA characterizations. The judge reportedly denied most of the defense’s objections.
Why this case matters beyond the courtroom
The Birchmore case has become one of the most closely watched trials in Massachusetts in years, and it is about more than one verdict. It is a test of how the justice system handles allegations of sexual exploitation inside its own ranks, the kind of abuse that thrives when the abuser wears a badge and the victim is a teenager in a mentorship program.
The federal legal theory is aggressive. The witness-killing count under federal law requires proof beyond a reasonable doubt that a killing was intended to prevent communication about a federal offense. The prosecution’s theory ties the alleged murder to underlying offenses including coercion and enticement and deprivation of rights under color of law. If the jury buys it, Farwell faces severe punishment. If the defense’s suicide theory holds, one of the most infamous unresolved deaths in recent Massachusetts memory ends in acquittal.
Testimony begins today. The prosecution is expected to call its first witness this morning, and The Enterprise News is reporting live from the courthouse. Whatever comes out over the next month will answer the question Sandra Birchmore’s family has been asking for five years: what really happened to her.
If you or someone you know has been a victim of sexual abuse, text “STRENGTH” to the Crisis Text Line at 741-741 to be connected to a certified crisis counselor.
For more US news coverage, see the US News archive on VIDX, and read our earlier coverage of the predawn federal raid on Rep. Ilhan Omar’s DC home.
