STOUGHTON, MA — The second week of testimony came and went on Friday in the federal trial of the former Stoughton police detective who is accused of killing Sandra Birchmore and staging her death to look like a suicide.
Matthew Farwell, 40, pleaded not guilty to charges of killing a witness or victim and causing the death of a child in utero. Prosecutors say Farwell strangled the pregnant 23-year-old in her Canton apartment on Feb. 1, 2021, to prevent her from disclosing a sexual relationship that began when she was 15.
The defense acknowledges Farwell had an affair with Birchmore but maintains that he did not kill her.
Here are five things to know about the trial as of Friday:
Federal prosecutors officially rested their case Wednesday after presenting testimony from more than 38 witnesses over 12 days.
The federal government's case centers on allegations that Farwell sexually exploited Birchmore beginning when she was a minor, then killed her when he believed their relationship could be exposed. He is charged with killing a witness or victim and causing the death of Birchmore's unborn child, according to the superseding indictment.
Jurors saw surveillance video showing Farwell entering Birchmore's apartment building at 9:14 p.m. on the night prosecutors say she was killed.
Digital forensic expert Jessica Hyde testified that Birchmore's phone recorded its final movement at about 9:40 p.m. Farwell was recorded leaving the building about three minutes later, Boston.com reported.
Prosecutors contend Birchmore was killed during that period. Farwell's attorneys say he visited the apartment to end their relationship.
Birchmore met Farwell through the Stoughton Police Explorers program, which she joined when she was 12. Trial testimony and messages presented in court indicated the sexual relationship began when Birchmore was 15 and Farwell was 27, according to The Associated Press.
Jurors also heard evidence that Farwell and Birchmore exchanged about 40,000 messages over the years. William Farwell, Matthew Farwell's twin brother, testified that Birchmore told him the relationship began when she was 15.
The state medical examiner's office initially classified Birchmore's death as a suicide. Dr. Maria Capó Martínez, who performed the autopsy, testified that police provided limited information and did not give her evidence suggesting a possible homicide. The official manner of death was later changed to undetermined, WHDH reported.
A prosecution expert testified that Birchmore was strangled with a duffel bag strap and that the scene was staged. The defense disputes that conclusion and maintains Birchmore died by suicide.
The original police response has also faced scrutiny. State investigators briefly interviewed Farwell and did not take notes, examine him for injuries or obtain a DNA sample, according to the AP's trial report.
The defense began calling witnesses Wednesday and has presented testimony about Birchmore's previous mental health struggles.
A former college supervisor testified that Birchmore told him she had attempted suicide in 2017.
Former boyfriend William Kilroy testified that she discussed suicide and made threats during their relationship. But Kilroy said he did not believe she would take her own life and never saw her attempt to harm herself, according to The Boston Globe.
Other witnesses offered a different picture.
Birchmore's therapist testified that she did not consider Birchmore a suicide risk and said Birchmore appeared excited about becoming a mother during an appointment one day before her death, WHDH reported.
The defense called forensic psychiatrist Dr. Melisa Piasecki on Friday. Closing arguments could begin next week, according to the Associated Press.
Catch up on Patch's previous coverage of the trial with a day-by-day breakdown of testimony:
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