Jury hears final case for ex-officer accused of murdering pregnant woman
Prosecutors argue that Matthew Farwell killed Sandra Birchmore in 2021 to hide an illicit relationship, while the defense maintains she died by suicide.
By Neha Kapoor ·
Closing arguments began Friday in federal court in Boston, marking the final stage of a trial that will determine whether former Massachusetts police detective Matthew Farwell murdered a 23-year-old teacher's aide. The verdict will decide the fate of the 40-year-old officer, who stands accused of killing Sandra Birchmore in 2021 after learning she was pregnant. If found guilty, Farwell faces a federal homicide conviction, a charge that local prosecutors had previously declined to bring.
Prosecutors contend that Farwell, a married detective with the Stoughton Police Department, strangled Birchmore to prevent her from revealing that he had begun sexually abusing her when she was 15. They argue he staged her death as a suicide to cover his tracks. The defense team acknowledges Farwell had an extramarital relationship with Birchmore but asserts he did not kill her and that their sexual relationship began only after she became an adult. They argue the evidence supports a finding of suicide.
The case hinges on conflicting medical evidence and digital records. Dr. William Smock, an expert for the prosecution, testified that Birchmore was strangled with a duffel bag strap and struggled before dying. In contrast, Dr. Thomas Andrew, the defense expert and former chief medical examiner in New Hampshire, testified that the injuries indicated hanging. The state medical examiner initially ruled the death a suicide based on police reports but has since changed the official manner of death to undetermined.
Digital forensics played a central role in establishing a timeline. An expert testified that Birchmore’s phone stopped moving at 9:40 p.m. on February 1, 2021. Three minutes later, lobby security cameras recorded Farwell leaving her building. Investigators recovered approximately 40,000 texts between the two, which included discussions about their sexual history and arguments over the pregnancy. The messages showed Birchmore pressing Farwell to father a child and threatening to inform his wife.
The FBI took over the investigation in 2023 after finding the local police probe rushed and compromised. Investigators noted that Farwell was interviewed for only 15 minutes in a parking lot without notes or DNA samples. His twin brother, Billy Farwell, testified that the lead investigator, a family friend, said he needed the case closed like he needed a bullet in the head. The trial also revealed that a paternity test showed a different man had fathered Birchmore’s child, a fact that complicates the narrative presented by the defense.
