A former Massachusetts police officer was convicted Tuesday of killing Sandra Birchmore, a pregnant 23-year-old woman he had sexually exploited since she was a teenager, in a case that prosecutors say involved an attempt to cover up years of abuse, according to the Department of Justice (DOJ).
Matthew Farwell, 41, was found guilty by a federal jury in Boston of killing a witness or victim and causing the death of Birchmore’s unborn child. Prosecutors said he strangled Birchmore at her apartment on Feb. 1, 2021, and staged the scene to make her death appear to be a suicide.
Farwell met Birchmore through the Stoughton Police Department’s Explorer program, which introduces young people to law enforcement careers. She joined the program at 12, and Farwell later served as an instructor after becoming a police officer in 2012.
According to evidence presented at trial, Farwell began sexually exploiting Birchmore when she was 15 and continued having sex with her after she became an adult. Prosecutors also said he had sexual encounters with her while working as a police officer.
The case took a significant turn in January 2021, when someone contacted the Stoughton Police Department about Farwell’s relationship with Birchmore. Prosecutors said Farwell became angry after learning about the complaint and exchanged a series of threatening and angry text messages with her.
Birchmore was pregnant at the time, and both she and Farwell believed he was the father. Witnesses testified that he had become aggressive toward her during arguments about the pregnancy.
On the night of her death, surveillance footage showed Farwell entering her apartment building shortly after 9 p.m. and leaving about 29 minutes later. Investigators found that Birchmore’s phone stopped recording movement at approximately 9:40 p.m., while Farwell was still inside the building.
Her death was initially classified as a suicide by state authorities. The FBI later reopened the investigation after receiving information from witnesses in October 2023. Farwell was arrested and federally charged in August 2024.
Farwell’s defense attorneys argued that Birchmore died by suicide and denied that he killed her. He had pleaded not guilty to the charges.
U.S. District Court Chief Judge Denise J. Casper scheduled Farwell’s sentencing for Feb. 3, 2027. The federal charges carry potential life imprisonment.