Matthew Farwell Convicted in the Death of Sandra Birchmore: The Evidence, the Elements and the Verdict

By Attorney Joe Serpa | Georgetown University Law Center

On Tuesday, November 10, 2026, a federal jury in Boston found former Stoughton police officer Matthew Farwell guilty on both counts of the superseding indictment that charged him in the death of Sandra Birchmore, according to WBUR. Count One charged him with killing a witness or victim, 18 U.S.C. § 1512(a)(1)(C). Count Two charged him with causing the death of Ms. Birchmore’s unborn child, 18 U.S.C. § 1841. The jury of eight men and four women returned its verdict at about 2 p.m., according to Boston.com.

The jury began deliberating on the afternoon of Friday, November 6, after closing arguments, according to Boston.com. On Monday, November 9, it reported that it was deadlocked. Chief Judge Denise J. Casper sent the jurors home for the day, and they resumed deliberating on Tuesday, according to WBUR. They reached their verdict on their second full day of deliberations, according to NBC Boston.

Our October 16 post on the trial describes Ms. Birchmore’s life, the three Stoughton officers, the investigation that ruled her death a suicide, and the federal charges. This post explains what the government had to prove on each count, the evidence the jury heard, and how the jury likely reached its verdict.

What the Government Had to Prove

The news reports of the trial do not describe Judge Casper’s instructions to the jury on the elements of each count. The elements below come from the statutes and from the Supreme Court’s decision in Fowler v. United States.

Count One: Killing a Witness or Victim

Section 1512(a)(1)(C) makes it a federal crime to kill another person with intent to prevent any person from telling a federal law enforcement officer about the commission or possible commission of a federal offense. To convict Mr. Farwell on Count One, the jury had to find three things beyond a reasonable doubt.

First, the jury had to find that Mr. Farwell killed Ms. Birchmore. The central dispute at trial was whether she was strangled or died by suicide. Second, the jury had to find that he killed her with malice aforethought, the state of mind required for murder. 18 U.S.C. § 1111(a). Third, the jury had to find that he killed her with intent to prevent her, or anyone else, from reporting a federal offense to a law enforcement officer.

The indictment named three federal offenses that Mr. Farwell allegedly wanted to hide. They are deprivation of rights under color of law, 18 U.S.C. § 242, coercion and enticement of a minor, 18 U.S.C. § 2422(b), and wire fraud, 18 U.S.C. § 1343.

The government did not have to prove that Mr. Farwell knew a report would go to a federal officer. 18 U.S.C. § 1512(g). Where a defendant kills to prevent a report to law enforcement in general, the government must show a reasonable likelihood that at least one relevant communication would have been made to a federal officer. Fowler v. United States, 563 U.S. 668, 677 (2011). The likelihood must be more than remote, outlandish, or simply hypothetical. The government need not prove that a federal report was more likely than not. Id. at 678.

Count Two: The Death of the Unborn Child

Section 1841 makes it a separate crime to cause the death of a child in utero while committing one of the federal offenses the statute lists. Section 1512 is one of those offenses. 18 U.S.C. § 1841(b)(1). Count Two therefore depended on Count One. A finding that Mr. Farwell killed Ms. Birchmore in violation of § 1512, and that the killing ended her pregnancy, supported a conviction on Count Two. The government did not have to prove that he knew she was pregnant or that he intended to cause the death of the child. 18 U.S.C. § 1841(a)(2)(B). Ms. Birchmore had in fact told Mr. Farwell that she was pregnant.

The Evidence at Trial

The jury heard from about 50 witnesses and saw about 500 exhibits over nearly a month, according to the Associated Press. Mr. Farwell did not testify.

How Ms. Birchmore Died

Dr. William Smock, a medical expert called by the government, testified that Ms. Birchmore died of asphyxia from strangulation and that she was the victim of a homicidal act, according to Boston 25 News. He testified that the right side of her hyoid bone, a small bone in the neck, was fractured inward. He said that injury is consistent with strangulation and not with a partial hanging. He also testified that a mark on her upper chest matched the clasp of the duffel bag strap, which was tied to the door handle when police found her. He concluded that the clasp made the mark before the strap was tied to the door, and he called the scene altered, according to Boston 25 News and the Boston Globe.

The state medical examiner, Dr. María Del Mar Capó-Martínez, testified that she first ruled the death a suicide by hanging and later changed the manner of death to undetermined. She testified that she had not seen the surveillance video or the phone data when she made her first ruling, according to WJAR.

Dr. Thomas Andrew, a former chief medical examiner of New Hampshire called by the defense, testified that the manner of death was undetermined and that the autopsy findings favored suicide, according to the Boston Globe. He testified that the hyoid could have broken after death or during convulsions, according to WPRI. On cross-examination, he agreed that strangulation can occur without external injuries and that a hanging can be staged after death, according to NBC Boston. NBC Boston also reported that he acknowledged that hyoid fractures are far more common in strangulations than in hangings. Other defense experts testified that the hyoid fracture did not show one cause or the other and that the photographs of the chest mark were inconclusive, according to Boston.com.

The Night of February 1, 2021

Building surveillance video showed Mr. Farwell entering Ms. Birchmore’s building at about 9:14 p.m. in a surgical mask and a hood, and leaving at about 9:43 p.m., according to Boston.com and the Boston Globe. A forensic examiner testified that Ms. Birchmore sent her last text message at 9:13 p.m., telling him the door was open. Her phone recorded its last movement at 9:40 p.m., according to WJAR. The Associated Press reported that her phone stopped moving about three minutes before the lobby camera showed Mr. Farwell leaving. A defense expert testified that step data should be interpreted cautiously, according to WPRI.

The January 20 Call and the Motive

A former Stoughton police dispatcher testified that he took the January 20, 2021 call from a woman who suggested that Mr. Farwell had a relationship with her friend, and that he told Mr. Farwell about it. The dispatcher testified that Mr. Farwell became visibly upset and told him never to talk about it again, according to Boston.com and WJAR. An FBI agent testified that Mr. Farwell texted Ms. Birchmore that day that her friend had called his job, according to WJAR.

The jury also saw text messages in which Ms. Birchmore threatened in October 2020 to tell Mr. Farwell’s wife about the relationship. The jury saw his reply to her news of the pregnancy, that she was the worst person on the face of the earth, according to WJAR and Boston.com. An FBI agent testified that there were no texts, searches or journal entries about suicide on the night Ms. Birchmore died, and that she had been texting about baby shower themes, according to Boston 25 News.

William Farwell, Mr. Farwell’s twin brother, testified under a grant of immunity. He admitted that he had a sexual relationship with Ms. Birchmore when she was an adult, according to NBC Boston. He also testified that his brother later told him he had wiped his phones, according to Boston 25 News. An FBI examiner testified that a phone linked to Mr. Farwell searched in February 2021 whether deleted messages could be recovered, according to Boston.com. Jason Pickard, whom DNA testing identified as the father of the child, testified that he encouraged Ms. Birchmore to report Mr. Farwell and that she was not suicidal, according to WJAR.

The Defense Case

The defense presented evidence of Ms. Birchmore’s mental health history through a forensic psychiatrist, including a suicide attempt in early adolescence and a psychiatric hold in May 2020, according to the Boston Globe. The jury also heard about a 2017 journal entry that read as a suicide note, according to WJAR. In closing, defense attorney Kimberly Stevens argued that Ms. Birchmore took her own life. She also argued that Ms. Birchmore was never going to go to federal law enforcement or any other law enforcement, according to Boston.com.

The Closing Arguments

Assistant United States Attorney Brian Fogerty argued that Mr. Farwell planned the killing after he learned of the January 20 call. He pointed to evidence that Mr. Farwell obtained a key to her apartment, inspected her closet and bathroom, and timed his visit to a coming snowstorm, according to CBS Boston and Boston.com. Ms. Stevens answered that there was no evidence that Mr. Farwell ever had a key, according to Boston.com.

How the Jury Likely Reached Its Verdict

Jurors do not explain their verdicts, and the public reports do not show what the jurors discussed. The verdict and the evidence nonetheless suggest how the jury resolved each element.

The jury first had to decide how Ms. Birchmore died. The medical experts disagreed, and the medical examiner had changed her ruling to undetermined. The jury likely did not decide the cause of death on the medical testimony alone. The defense’s own expert agreed on cross-examination that strangulation can occur without external injuries and that a hanging can be staged after death. Once the medical evidence permitted a finding of strangulation, the jury likely relied on the timeline to decide the question. Ms. Birchmore’s phone stopped moving while Mr. Farwell was still in the building, and he left minutes later with his hood up and his mask on. The defense theory required the jury to accept that Ms. Birchmore took her own life in the few minutes after he left. The phone data made that theory difficult to accept.

The jury next had to decide whether Mr. Farwell acted with malice aforethought and with intent to silence Ms. Birchmore. The order of events supported both findings. A friend called the Stoughton police on January 20, 2021. Mr. Farwell learned of the call that day and texted Ms. Birchmore that her friend had called his job. Ms. Birchmore had threatened to tell his wife, and she was preparing for the birth of a child she believed was his. Twelve days after the call, she was dead. The jury likely inferred that he killed her because she could expose him. The evidence that he wiped his phones and searched whether deleted messages could be recovered likely reinforced that inference.

The federal element was the strongest defense argument. No witness testified that Ms. Birchmore contacted or planned to contact the FBI. The defense argued that she never intended to report anyone. Under Fowler, however, the government did not have to prove that a federal report was more likely than not. It had to show only a reasonable likelihood that a report would have reached a federal officer. A report that a police officer began a sexual relationship with a 15-year-old girl he met through his department’s Explorers program describes possible federal offenses, including deprivation of rights under color of law and coercion and enticement of a minor. A former Stoughton deputy chief testified that the department would likely have opened an investigation had it learned of the relationship while Ms. Birchmore was alive, and that he later alerted the FBI, according to the Boston Globe and Boston.com. The jury likely concluded from that evidence that a report of Mr. Farwell’s conduct was reasonably likely to reach federal investigators.

The deadlock note on Monday shows that at least one juror was not yet persuaded on at least one element. The public reports do not show which element divided the jurors. Judge Casper told the jurors to take the time they need, and they returned unanimous verdicts on both counts the next afternoon, according to the Boston Globe and Boston.com. The conviction on Count Two rested on the same findings as Count One, because the killing of Ms. Birchmore ended her pregnancy.

What Happens Next

Judge Casper scheduled sentencing for February 3, 2027, according to WBUR and Boston.com. The Associated Press and the Boston Globe reported that the conviction on Count One requires a life sentence. Under 18 U.S.C. § 1512(a)(3)(A), the punishment for a killing is the punishment that 18 U.S.C. §§ 1111 and 1112 provide. A defendant convicted of first-degree murder under § 1111 receives death or life imprisonment, and the Department of Justice is not seeking death. The public reports do not say whether the jury was instructed on first-degree murder alone or also on second-degree murder, which permits a sentence of any term of years.

Federal law requires a judge to detain a defendant found guilty of a crime of violence, or of an offense punishable by life imprisonment, while the defendant awaits sentencing, unless narrow exceptions apply. 18 U.S.C. § 3143(a)(2). Mr. Farwell has been held without bail since his arrest in August 2024.

The defense may ask Judge Casper to enter a judgment of acquittal or to order a new trial. Both motions are due within 14 days after the verdict, unless the judge extends the deadline. Fed. R. Crim. P. 29(c)(1), 33(b)(2). A motion for a new trial based on newly discovered evidence may be filed up to three years after the verdict. Fed. R. Crim. P. 33(b)(1).

After sentencing, Mr. Farwell may appeal to the United States Court of Appeals for the First Circuit. The notice of appeal is due within 14 days after the judgment is entered. Fed. R. App. P. 4(b)(1)(A).

The civil suit brought by Ms. Birchmore’s estate against the Town of Stoughton, Mr. Farwell and others is set for a hearing after the federal trial, according to NBC Boston. Later posts in this series will cover the sentencing.

Key Takeaways

• On November 10, 2026, a federal jury in Boston convicted former Stoughton police officer Matthew Farwell of killing Sandra Birchmore to prevent a report of federal offenses, 18 U.S.C. § 1512(a)(1)(C), and of causing the death of her unborn child, 18 U.S.C. § 1841.
• To convict on Count One, the jury had to find that Mr. Farwell killed Ms. Birchmore with malice aforethought and with intent to prevent a report of a federal offense. Under Fowler v. United States, the government had to show a reasonable likelihood that a report would have reached a federal officer.
• The medical experts disagreed on whether Ms. Birchmore was strangled. Phone data showed that her phone stopped moving while Mr. Farwell was still in her building.
• Mr. Farwell learned of a friend’s call to the Stoughton police about the relationship twelve days before Ms. Birchmore died.
• Sentencing is scheduled for February 3, 2027.

Related Serpa Law Office Resources

• When the Police Protect and Serve Only Themselves: Sandra Birchmore and the Federal Trial of Matthew Farwell
• Intimidation of a Witness (G.L. c. 268, § 13B)
• Strangulation or Suffocation in Massachusetts (G.L. c. 265, § 15D)
• Opening Statements and Closing Arguments in Massachusetts Criminal Trials
• Cross-Examination in Massachusetts Criminal Trials
• Massachusetts Text Message and Phone Evidence FAQs

This post is for general informational purposes only and is not legal advice. It is based solely on public court proceedings, published decisions and published news reporting on the trial. Reading it does not create an attorney-client relationship. This may constitute attorney advertising.