In Brief
Jury selection began October 6, 2026, in the Boston federal trial of former Stoughton police detective Matthew Farwell. He’s accused of killing Sandra Birchmore, 23, in her Canton, Massachusetts, apartment on February 1, 2021, and staging her death to look like a suicide. She was pregnant. He’s charged with killing a witness or victim to keep information about federal crimes from reaching federal law enforcement, and with causing the death of her unborn son. He has pleaded not guilty and says she took her own life. The death penalty isn’t on the table.
What’s next
Jury selection continues October 7, and questioning of prospective jurors is set for October 8 and 9 before Chief U.S. District Judge Denise J. Casper. Prosecutors expect about 20 trial days. Where the case stands.
Sandra Birchmore’s death was ruled a suicide in 2021. Now a federal jury is being picked in Boston to decide whether Matthew Farwell, a Stoughton officer who volunteered with and later taught the police youth program she joined at 12, strangled her and staged the scene.
He isn’t charged with murder under Massachusetts law. The federal charge asks two questions. Did he kill her, and did he do it to keep information about federal crimes away from federal law enforcement? That second question, and a cause of death that’s already been officially changed once, are where this trial is fought.
On This Page
Where the Case Stands
Coming up
October 7, jury selection continues. October 8 and 9, the judge and lawyers question prospective jurors. Each side gets 40 minutes for its opening statement.
October 6, 2026
Dozens of prospective jurors filled out questionnaires, NBC 10 News reported, before voir dire, the questioning that decides who sits.
October 1, 2026
Judge Casper again refused to move the trial out of Massachusetts, ruling the defense hadn’t shown pretrial publicity would keep Farwell from a fair trial there.
September 17, 2026
The judge ruled that Birchmore’s out-of-court statements can come in, conditionally, and denied a defense challenge to testimony from pathologist Dr. Michael Baden.
Spring 2026
The state medical examiner’s office amended the death certificate from suicide to “undetermined,” as Boston 25 News reported on May 1.
March 9, 2026
Judge Casper denied Farwell’s motion to dismiss the indictment.
December 9, 2025
A court filing said the Attorney General had directed prosecutors not to seek the death penalty, CBS News reported.
October 28, 2025
A grand jury returned a superseding indictment, a replacement charging document, adding the unborn child count.
August 28, 2024
The FBI arrested Farwell the day after a federal grand jury indicted him.
Why a Killing Became a Federal Case
The Norfolk District Attorney’s office concluded Birchmore took her own life, and the FBI opened its own investigation in 2023, according to Boston.com. The charge it produced is 18 U.S.C. § 1512(a)(1)(C). It punishes anyone who kills another person with intent to “prevent the communication by any person to a law enforcement officer or judge of the United States of information relating to the commission or possible commission of a Federal offense.”
The indictment names three federal offenses Farwell allegedly wanted kept quiet. They’re deprivation of rights under color of law under 18 U.S.C. § 242, coercion and enticement of a minor under § 2422(b), and wire fraud under § 1343. Section 242 is where his badge comes in. It reaches anyone who, “under color of any law,” willfully deprives a person of rights protected by the Constitution. The indictment alleges he had sex with Birchmore before she turned 16, sometimes during shifts he was paid to work, and that on January 20, 2021, a friend of hers called the Stoughton Police Department to report it. A department employee told Farwell about the call. Twelve days later, prosecutors say, he killed her.
Wanting to stop a report to the police in general isn’t enough. In Fowler v. United States, 563 U.S. 668, 677-78 (2011), the Supreme Court held that the government has to show it was “reasonably likely under the circumstances that (in the absence of the killing) at least one of the relevant communications would have been made to a federal officer.” Judge Casper ruled that the indictment didn’t need to allege that likelihood because the government must prove it at trial. United States v. Farwell, No. 1:24-cr-10259-DJC (D. Mass. Mar. 9, 2026), docket entry 97. The defense can press that point. The friend’s call went to a local department, and the jury has to find a federal report was reasonably likely, not just possible.
Suicide, Undetermined, or Homicide
The original death certificate listed the cause as “asphyxia by hanging” and the manner as suicide. The amended one says “asphyxia” and “undetermined.” Dr. Maria Capó Martinez, who did the autopsy, ruled suicide after asking for investigative updates, and she hadn’t been told the death was “a potential homicide or a suspicious case,” according to the prosecution’s trial brief as reported by NBC Boston. Prosecutors say she’ll testify to injuries more common in homicides than suicides, including a fractured hyoid, a small bone in the neck.
There was no second autopsy. Birchmore was cremated, and Capó Martinez was the only doctor who examined her body, the Boston Globe reported. Baden, retained by a lawyer for her estate, and Dr. William Smock reviewed the records. My page on medical and autopsy evidence covers how this kind of testimony gets tested.
The defense says Birchmore killed herself and points to her mental health history. The judge is letting her counselor and her OB/GYN describe treating her, including screening for suicide risk, and said the defense can cross-examine with studies on whether suicide is predictable. “Undetermined” isn’t a homicide finding. The government has to prove beyond a reasonable doubt that she was killed.
Her Own Words in the Courtroom
Hearsay, an out-of-court statement offered for its truth, usually can’t come in. Federal Rule of Evidence 804(b)(6) makes an exception for a statement offered against a party that “wrongfully caused” the speaker’s unavailability as a witness “and did so intending that result.” That’s called forfeiture by wrongdoing.
Judge Casper is admitting Birchmore’s statements conditionally. At the close of the evidence she’ll decide whether the government proved the rule’s elements by a preponderance, meaning more likely than not. If it didn’t, her order lists the remedies: striking evidence, a curative instruction, or a judgment of acquittal if what’s left can’t support a conviction. The finding she has to make overlaps with the question the jury decides.
The Messages and the Building
Prosecutors reviewed about 40,000 messages between Farwell and Birchmore, NBC Boston reported. Their trial brief says he entered her building about six minutes after asking if he could “come by for a second,” wearing a hood and a surgical mask. It also says he wouldn’t let police search his personal phone, said his messages with her had been deleted, and searched on his work phone about recovering deleted iPhone messages with police software.
The defense has its own fact to work with. DNA testing excluded Farwell as the father, according to Boston.com. Paternity isn’t an element, but it may bear on the motive prosecutors describe. My page on homicide charges explains how motive and intent differ.
The Unborn Child Count
Under 18 U.S.C. § 1841(a)(1), a person who violates a listed federal law “and thereby causes the death of” a child “in utero” commits a separate offense. Section 1512 is on the list. Section 1841(a)(2)(B) says the government doesn’t have to prove he knew she was pregnant or meant to harm the child. Because count two rests on conduct that violated § 1512, it depends on the first count.
Count one charges a premeditated killing. Federal murder law, 18 U.S.C. § 1111(b), punishes first-degree murder “by death or by imprisonment for life,” and death is off the table. The judge has barred any evidence of penalties at trial.
Common Questions
Why is the Sandra Birchmore case in federal court?
The charge is that Farwell killed her to stop information about federal crimes, including deprivation of rights under color of law, from reaching federal law enforcement. That federal link is an element the government has to prove.
Is Matthew Farwell facing the death penalty?
No. A court filing reported December 9, 2025, says the Attorney General directed prosecutors not to seek it, and the unborn child statute bars it on that count.
How long will the Farwell trial last?
Prosecutors expect about 20 trial days in Boston. Cameras aren’t allowed in the courtroom.
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Further Reading
- 18 U.S.C. § 1512, tampering with a witness, victim, or an informant, Legal Information Institute
- 18 U.S.C. § 1841, protection of unborn children, Legal Information Institute
- Fowler v. United States, 563 U.S. 668 (2011), CourtListener
- Superseding indictment, United States v. Farwell (D. Mass. Oct. 28, 2025), CourtListener
- Memorandum and Order denying motion to dismiss (D. Mass. Mar. 9, 2026), CourtListener
- Why the Sandra Birchmore case is in federal court, Boston.com, September 29, 2026
- What prosecutors’ trial brief says, NBC Boston, August 6, 2026
- No death penalty for Matthew Farwell, CBS News Boston, December 9, 2025
WRITTEN AND REVIEWED BY
Rory Safir, ACS-CHAL Forensic Lawyer-Scientist
He is the author of The Florida DUI Trial Manual, an NHTSA-qualified instructor in the standardized field sobriety exercises, faculty of the National College for DUI Defense, and a former Assistant Public Defender in the Thirteenth Judicial Circuit.
This post is general information about the law, not legal advice, and it does not create an attorney-client relationship. The law discussed is 18 U.S.C. sections 242, 1111, 1343, 1512, 1515, 1841 and 2422(b); Federal Rule of Evidence 804(b)(6); Fowler v. United States, 563 U.S. 668 (2011); and the superseding indictment (docket entry 63), the March 9, 2026 Memorandum and Order (docket entry 97) and the docket in United States v. Farwell, No. 1:24-cr-10259-DJC (D. Mass.), read together with published reports of Boston.com, NBC Boston, CBS News, the Boston Globe, Boston 25 News, WHDH, WBUR and NBC 10 News, as of October 7, 2026.
