A former police detective was convicted Tuesday of murdering a pregnant Massachusetts woman, Sandra Birchmore, to keep her from revealing that he had sexually abused her when she was 15.

Matthew Farwell, 40, was found guilty of strangling Birchmore on Feb. 1, 2021 - 12 days after a tipster called the suburban Boston police department where he worked and reported that they'd had an improper relationship.

Birchmore, who was 23 when she died, had been in a tumultuous relationship with the detective, whom she first met while participating in a Stoughton Police Department youth program as a child.