Former Officer Charged With Killing Woman Whose Death Was Ruled a Suicide

When Sandra Birchmore, a young pregnant woman, was found dead in her apartment in Canton, Mass., in 2021, it was initially ruled a suicide.

But the case took a grim turn on Wednesday when federal prosecutors charged that the 23-year-old had actually been killed by a former police officer who she said had gotten her pregnant, to cover up a sexual relationship that started when she was underage.

The former officer, Matthew Farwell, 38, was arrested on Wednesday morning and charged with one count of killing a witness or victim. He pleaded not guilty, according to prosecutors, and will remain in custody until a detention hearing next month.

Mr. Farwell got to know Ms. Birchmore while he was working as an instructor for the Stoughton Police Department’s Explorers Academy, a program for young people to learn about careers in law enforcement. Prosecutors said that Mr. Farwell had begun to groom Ms. Birchmore soon after she joined the program in 2010.

“This grooming culminated in Farwell raping Birchmore in April 2013, when she was only 15 years old,” according to an affidavit from an F.B.I. special agent. Mr. Farwell was 27 at the time, the agent said.

The sexual contact continued for years, according to court documents, and in December 2020 Ms. Birchmore learned that she was pregnant. The next month, a friend of Ms. Birchmore’s called the Stoughton Police Department and mentioned the illicit relationship, according to the affidavit, and one of Mr. Farwell’s colleagues informed him of that call.

On Feb. 1, 2021, prosecutors say, Mr. Farwell entered Ms. Birchmore’s apartment and strangled her.

“When it became clear to Mr. Farwell that he could no longer control Sandra Birchmore, he allegedly silenced her, permanently,” Joshua S. Levy, the acting U.S. attorney for Massachusetts, said at a news conference on Wednesday. He added, “He used his knowledge and experience as a law enforcement officer to stage her death to look like a suicide.”

A lawyer for Mr. Farwell could not immediately be reached for comment on Wednesday.

The case, set in the same suburbs south of Boston where the high-profile Karen Read murder trial unfolded this summer, has drawn close attention from Ms. Read’s supporters, fueling their suspicions about corruption in local law enforcement.

After trial testimony revealed last month that a state police trooper had sent vulgar, sexist text messages about Ms. Read while investigating the death of her boyfriend, a Boston police officer, local outrage about police misconduct surged.

The news of the indictment in Ms. Birchmore’s death added new fervor to the outcry, and renewed longstanding questions about the law enforcement culture that fostered her abuse and allegedly resulted in her death.

In 2022, after an internal affairs investigation, three Stoughton police officers, including Mr. Farwell, were accused of having inappropriate relationships with Ms. Birchmore, according to the police chief. All three have since resigned.

As the investigation continued, federal agents found evidence that cast doubt on the idea that Ms. Birchmore had been suicidal. In fact, they said, she had seemed excited about the pregnancy.

“In the hours leading up to Sandra’s death, she reached out to a photographer to inquire about booking a newborn photo shoot,” Stephen J. Kelleher, the assistant special agent in charge of the F.B.I.’s Boston office, said at the news conference. “She also reached out to a friend about obtaining baby clothes.”

He added that Ms. Birchmore had been in the middle of doing laundry when she died, with one load of clothes in the washing machine and another in the dryer.

If convicted, Mr. Levy said, Mr. Farwell would face a minimum sentence of life in prison.

“This is a horrific situation,” the Stoughton police chief, Donna McNamara, said at a separate news conference on Wednesday. “Sandra Birchmore will receive no justice in life.”

Jenna Russell contributed reporting.