Jury selection is scheduled to begin Tuesday, Oct. 6, in the federal trial of former Stoughton police officer Matthew Farwell, who is accused of killing Sandra Birchmore and her unborn child in February 2021.

Farwell has pleaded not guilty. Prosecutors allege he strangled Birchmore in her Canton apartment and arranged the scene to resemble a suicide. His defense maintains that Birchmore died by suicide.

Chief U.S. District Judge Denise J. Casper plans to seat 12 jurors and four alternates at the John J. Moakley Federal Courthouse in Boston. Prospective jurors will complete questionnaires Tuesday, with individual questioning expected to begin Thursday.

Opening statements could begin Friday, Oct. 9, depending on how quickly a jury is selected. Proceedings are expected to last approximately 20 trial days, according to The Enterprise’s report on the final pretrial hearing.

Two federal charges

Farwell faces charges of killing a witness or victim and causing the death of a child in utero. The second charge was added in an Oct. 28, 2025, superseding indictment.

Prosecutors allege that Farwell killed Birchmore on or about Feb. 1, 2021, to prevent information about his alleged federal offenses from reaching law enforcement.

According to the U.S. attorney’s office, Birchmore joined the Stoughton Police Explorers Program at age 12. Farwell served as an instructor, and prosecutors allege he began sexually abusing her when she was 15.

Birchmore was 23 and approximately eight to 10 weeks pregnant when she died, according to federal charging documents. She had told Farwell he was the father. Subsequent DNA testing excluded him as the biological father, Boston 25 News reported.

Medical finding changed

The state medical examiner initially classified Birchmore’s death as a suicide.

The amended death certificate lists her manner of death as “undetermined” and her cause of death as asphyxia, replacing the earlier finding of asphyxia by hanging. The medical examiner’s office confirmed the changes in reporting published May 1.

Digital evidence remains disputed

At the Oct. 2 pretrial hearing, attorneys disputed how broadly Farwell had authorized investigators to search his personal iPhone in 2021.

The defense argued that his consent covered digital evidence relevant to Birchmore’s death. Prosecutors said the authorization was limited to communications between Farwell and Birchmore and that investigators initially reviewed only that material.

Prosecutors said they would examine additional phone data following the defense’s broader interpretation of the consent. Casper left related questions about expert testimony unresolved at the hearing, The Enterprise reported.