TL;DR: An FBI agent read explicit text messages aloud in a Boston federal courtroom Friday as the murder trial of former Stoughton detective Matthew Farwell entered its second week. Farwell, 40, is accused of killing 23-year-old Sandra Birchmore — about eight weeks pregnant — in her Canton apartment in February 2021 and staging her death as a suicide. He has pleaded not guilty. Testimony resumes Monday.
The Matthew Farwell trial heard its most graphic testimony yet Friday, as FBI Special Agent Heidi Kelsch read aloud sexually explicit texts the former Stoughton police detective exchanged with Sandra Birchmore, the 23-year-old he is accused of strangling, the Enterprise reported. Jurors also learned Farwell had noted April 10, 2013 — the date prosecutors say he first had sex with Birchmore, when she was 15 and he was 27 — in his phone.
Farwell, 40, is charged with killing a witness to keep information about federal crimes from law enforcement, and with causing the death of Birchmore’s unborn child. He faces life in prison; the death penalty is not on the table. The trial before Chief U.S. District Judge Denise J. Casper at the Moakley Courthouse began with jury selection October 6 and should run about five weeks.
Why the Case Is in Federal Court
Farwell faces no state murder charge. Prosecutors allege he killed Birchmore to stop her reporting his sexual exploitation of her to federal authorities — a witness-killing charge under 18 U.S.C. § 1512 requiring jurors to find he both killed her and did it to silence her, legal analysis notes.
Birchmore was found dead February 4, 2021, a luggage strap around her neck tied to a closet doorknob. The death was first ruled a suicide and the Norfolk County DA declined to prosecute. The FBI arrested Farwell on August 28, 2024, after a federal expert found her injuries inconsistent with suicide; in April 2026 the medical examiner amended the manner of death to undetermined. Farwell has been held without bail since.
Prosecutors cite his DNA on the strap, his sperm in her underwear, and surveillance footage placing him at her building that night. Birchmore joined Stoughton’s police youth Explorer program at 12, where Farwell instructed; prosecutors say he groomed her for years before the relationship turned sexual in April 2013, a month before he married his wife Michelle.
Friday’s Testimony: Searches and Baby Names
Kelsch, of the FBI’s public corruption and civil rights squad, said the probe began in October 2023 after then-Stoughton Deputy Chief Brian Holmes raised concerns, WBZ NewsRadio reported. Agents reviewed hundreds of thousands of messages and interviewed about 130 witnesses. The investigation also ended the careers of Farwell’s twin brother William — decertified for lying about his own relationship with Birchmore — and former Deputy Chief Robert Devine.
Forensic expert Christopher Beckstrom detailed Farwell’s Google searches from February 9, 2021, the day he surrendered his phone to state police: “Can you revoke consent in Massachusetts?” and “Can delete iMessage be recovered cellbrite.” Jurors also saw Birchmore’s January 27, 2021 phone notes — baby names Madelyn, Nicole, Abby, Rose, Lilly, Elizabeth, Cayden and Matthew. Prosecutors say she was about eight weeks pregnant.
The Defense Says Suicide
Attorney Kimberly Stevens told jurors Farwell made “regrettable mistakes” but did not kill Birchmore: “Matthew Farwell did not kill Sandra Birchmore. He did not.” The defense says she died by suicide, alone and under financial strain, and alleges department bias — noting Sgt. Robert Kuhn’s admission he once said of Farwell, “I can’t wait to crush this mother (expletive).”
Prosecutor Torey Cummings countered in her opening that Farwell “lulled her into feeling safe so that he could kill her.” Kelsch returns to the stand Monday; with 16 jurors seated, a verdict is expected around mid-November. Conviction on the witness-killing count means mandatory life.
Frequently Asked Questions
Who is Matthew Farwell?
A 40-year-old former Stoughton, Massachusetts, police detective, arrested by the FBI in August 2024 and held without bail. He is on trial in Boston federal court, accused of killing Sandra Birchmore.
Who was Sandra Birchmore?
A 23-year-old from Canton who joined Stoughton’s police youth Explorer program at 12. Prosecutors say Farwell groomed and sexually exploited her for years. She was found dead February 4, 2021, about eight weeks pregnant.
What is he charged with?
Killing a witness to block information about federal crimes from reaching law enforcement, and causing the death of an unborn child. He has pleaded not guilty to both.
Why federal court?
The county DA declined to prosecute after the death was ruled a suicide. Prosecutors allege Farwell killed Birchmore to stop her reporting him to federal authorities.
What do prosecutors allege?
That Farwell strangled Birchmore in her Canton apartment on February 1, 2021, staging it as suicide with a luggage strap — citing his DNA on the strap, his sperm in her underwear, and surveillance footage.
What is the defense?
That Birchmore died by suicide, alone and under financial strain — and that Farwell’s “regrettable mistakes” did not include murder.
What happened Friday?
An FBI agent read explicit texts aloud; a forensic expert detailed Farwell’s searches about consent and deleted messages; jurors saw Birchmore’s baby-name list from days before her death.
When does the trial end?
The five-week trial could reach a verdict in mid-November. Conviction on the witness-killing charge carries mandatory life in prison.
