The Boston jury found Matthew Farwell guilty on Nov. 10 in the killing of Sandra Birchmore and the death of her unborn child.
The jury found Farwell guilty on the witness-or-victim killing charge and on a separate count concerning the unborn child’s death.
At trial, prosecutors described sexual exploitation beginning when Birchmore was 15 and said the two had sexual encounters while Farwell was on duty. They argued he wanted to prevent her from disclosing that conduct to authorities.
The superseding indictment says Farwell allegedly sought to prevent information about potential federal offenses from reaching law enforcement. It lists deprivation of rights under color of law, coercion and enticement, and wire fraud as possible crimes.
Birchmore joined the youth Explorers program run by Stoughton police at 12 in 2010, the Justice Department said. Farwell became a sworn officer and instructor in 2012.
Massachusetts authorities first ruled Birchmore’s death a suicide, according to the Justice Department. The amended death certificate listed asphyxia as the cause and left the manner undetermined. WBUR reported that Farwell’s defense argued Birchmore died by suicide and cited her mental-health history.
Ted E. Docks, special agent in charge of the Boston Division of the Federal Bureau of Investigation (FBI), said the verdict held Farwell responsible for a “calculated attempt to silence” Birchmore.
The Justice Department lists Feb. 3, 2027, as Farwell’s sentencing date. NBC Boston reported that the date is for a presentencing hearing, with the sentencing hearing to be set later.
