Closing arguments are expected Friday in the federal trial of a former Massachusetts police officer accused of killing a pregnant woman in 2021 to prevent her from revealing their sexual relationship, which began when she was 15. Prosecutors claim Matthew Farwell, then a married detective with the Stoughton Police Department, murdered Sandra Birchmore, 23, and attempted to stage her death as a suicide.
Farwell's defense acknowledges the extramarital relationship but denies he killed Birchmore, stating any sexual contact occurred after she became an adult. The trial is taking place in federal court in Boston because local prosecutors did not bring criminal charges.
Local police and Massachusetts State Police, some with personal ties to Farwell, initially ruled Birchmore's death a suicide. The state's medical examiner also made an initial suicide ruling, though the cause of death has since been changed to "undetermined." Friends and family of Birchmore, however, never believed she took her own life. Prosecutors presented evidence that Birchmore was excited about her pregnancy, planning a maternity shoot and baby shower, and had an ultrasound photo pinned to her refrigerator.
The FBI opened an investigation into Birchmore's death in 2023, prompted partly by a former deputy chief of the Stoughton Police Department. Federal investigators concluded the initial local probe was rushed and compromised, citing a brief interview with Farwell, a lack of notes, and the deletion of texts between Farwell and Birchmore before his phone was examined. Farwell's twin brother testified that the lead investigator, a family friend, expressed a desire to close the case quickly.
FBI analysis uncovered approximately 40,000 text messages between Farwell and Birchmore. Some texts reportedly discussed their sexual encounters when Birchmore was 15, an age below the age of consent in Massachusetts. Other messages indicated a contentious relationship, with Birchmore pressing Farwell about the pregnancy and threatening to inform his wife. A paternity test later revealed a different man was the father of Birchmore's child.
Evidence presented at trial suggests Birchmore's phone stopped moving at 9:40 p.m. on Feb. 1, 2021, shortly before security cameras recorded Farwell leaving her building. A prosecution expert testified that Birchmore's injuries were consistent with strangulation by a duffel bag strap. The defense presented their own expert who argued the evidence pointed to hanging and disputed the homicide determination. Farwell's lawyers contend he went to Birchmore's apartment to end their relationship and that she took her own life, citing her history of mental health challenges and suicide attempts.