Former Stoughton police officer Matthew Farwell has been charged with the murder of Sandra Birchmore, a 23-year-old pregnant woman, to conceal a longstanding sexual relationship that began when she was a minor. Farwell allegedly strangled Birchmore in February 2021 and staged her death to appear as a suicide after she informed him of her pregnancy. Birchmore had joined the Stoughton Police Explorers program at age 12, where Farwell, an instructor, began grooming and sexually exploiting her by age 15. Federal prosecutors have charged Farwell with 'killing a witness or victim,' a crime that could result in the death penalty or life imprisonment. The case, initially ruled a suicide, resurfaced after new evidence emerged, leading to Farwell's arrest following a federal investigation. Two other officers involved in inappropriate relationships with Birchmore resigned in 2022.