For years, Sandra Birchmore trusted the Massachusetts detective now accused of killing her

Former police detective Matthew Farwell, 39, was indicted in Massachusetts federal court after Sandra Birchmore's death on one count of killing a witness or victim.

The chief of a Massachusetts police department that’s been gripped by allegations of sexual misconduct and murder told “Dateline” that she felt “obligated” to share details unearthed by her investigators in the harrowing case of Sandra Birchmore, who authorities say endured years of abuse in a police youth program before her death at the hands of a former detective.

In her first media interview, Stoughton Police Chief Donna McNamara offered an apology and said she hopes Matthew Farwell, the ex-detective accused of sexually exploiting the one-time police “explorer” before allegedly strangling her and staging her death to look like a suicide, is held accountable and sent to prison if convicted.

Two other ex-Stoughton officers — a former deputy chief and Matthew Farwell’s twin, William Farwell — were also accused of having inappropriate relationships with Birchmore, who’d long admired law enforcement and was 23 and newly pregnant when she died Feb. 1, 2021.

“I am sorry that she was treated so horrifically by three men from my department,” McNamara told “Dateline.” “She didn’t deserve that.”

“They dehumanized her,” she added. “It’s vile.”