Who is Matthew Farwell, the Stoughton police officer accused of killing Sandra Birchmore?

On Wednesday, federal prosecutors alleged that Farwell used his role as a police officer and instructor in the Explorers program to harass Sandra Birchmore, who enrolled in the Stoughton Police Department's youth program in 2010 at age 12.

According to investigators, he raped Birchmore in April 2013. At the time, she was 15 and he was 27 and about to get married.

Farwell, 38, of Easton, was arraigned Wednesday on charges he is accused of strangling Birchmore, 23, in 2021 while she was expecting her first child and then staging her Canton apartment to make it look like she had committed suicide.

The allegations made by federal prosecutors contradicted an earlier finding by the state medical examiner's office, which had determined in May 2021 that Birchmore committed suicide.

When an FBI SWAT team arrested Farwell on Wednesday morning, he was driving a gravel truck through a Revere shopping center, authorities said. Wearing ripped jeans, work boots and a black T-shirt, he pleaded not guilty to the charge of killing a witness or victim. He was remanded in custody. A detention hearing is scheduled for Sept. 10.

His arrest followed a more than three-year investigation into Farwell's contacts with Birchmore. The married father and former patrol officers' union president resigned from the Stoughton Police Department in April 2022 pending the outcome of an internal investigation. In March, he gave up his authority to work as a police officer in Massachusetts as part of an agreement in which he admitted no wrongdoing. He is also the defendant in a wrongful death lawsuit brought by Birchmore's family.

If convicted, Farwell would have to spend the rest of his life in a federal prison and could face the death penalty. However, the acting U.S. Attorney for Massachusetts, Joshua Levy, said the U.S. Department of Justice has not yet decided whether to impose the death penalty.

Matthew Gregory Farwell was born in October 1985 at Norwood Hospital and attended Stoughton High School, where he was expelled for “poor attendance” and dropped out in 11th grade, according to Stoughton police records.

According to a redacted internal department investigation report, Farwell also had some problems with Stoughton police as a teenager.

He and his twin brother William, also a Stoughton police officer, were participating in the Stoughton Police Department's youth program. According to the report, they were caught posing as police officers and stopping cars, but it was not specified whether they faced any consequences.

Farwell worked a series of menial jobs before graduating from high school in Maine in 2004, according to Stoughton police records. He joined the Army that same year, where he trained as an explosives expert and was deployed to Afghanistan for six months in 2006, military records show. His military service ended in 2008.

Back in Massachusetts, was an officer with the Wellesley Police Department from 2008 to early 2012. The department recognized his service with several awards, including for resuscitating a man who collapsed while working out at a local gym, the Stoughton Journal reported in 2012.

He also remained involved in the Stoughton police youth program and volunteered with the Explorers, federal officials said. When he became a Stoughton police officer in March 2012, Farwell became an instructor in the program and turned his attention to Birchmore, they said.

“He befriended Sandra Birchmore, contacted her online, went to the library with her, became friends with her on Facebook and basically groomed her,” Levy said at a news conference Wednesday.

These arguments escalated until Farwell allegedly raped Birchmore and then, when she was an adult, had “a controlling and sometimes abusive relationship,” prosecutors wrote in court documents.

When Birchmore reached adulthood, Farwell allegedly asked her to pretend she was 13 or 14 years old during sex, prosecutors wrote. His twin brother William Farwell, a Stoughton police officer since 2017, and Robert C. Devine, a former deputy police chief who headed the department's youth program from 2002 to 2014, began meeting Birchmore in their patrol cars for sex, according to a decision in her family's wrongful death trial.

In October 2020, Birchmore learned that Farwell's wife was pregnant with the couple's third child, an FBI affidavit states. According to the document, she approached Farwell with an ultimatum.

They would have unprotected sex to conceive a child in exchange for Birchmore keeping their long-term relationships secret and protecting Farwell from potential consequences for allegedly committing rape, cheating on his wife and having sex while on duty as a Stoughton police officer, the affidavit states.

On December 28, 2020, Birchmore sent Farwell a photo of a poster she had decorated with baby animals, rainbow colors, and hearts. “Congratulations,” read the poster, a copy of which was included in the FBI affidavit. “We are [going] to be parents!”

Farwell “reacted badly” to the news of Birchmore's pregnancy and became violent, the affidavit states. Birchmore told one person that Farwell, who is 6'4″, told her “he wished [she] would just die,” put her in a headlock and grabbed her phone, FBI Special Agent Chenee Castruita wrote in the affidavit. Birchmore was 4 feet 6 inches tall, court records show.

Then on Jan. 20, 2021, one of Birchmore's friends called Stoughton police and said Farwell had had sex with Birchmore, the indictment says.

One of Farwell's colleagues, referred to in court documents as “Person 5,” told him about the call, Castruita wrote.

“Farwell immediately became angry and 'pissed off,'” she wrote.

According to the affidavit, he angrily confronted Birchmore about the call but later softened his tone.

For the first time, he asked Birchmore for an apartment key, despite previously saying he didn't want it, and spent time examining the apartment's bathroom and closet, Castruita wrote.

On Feb. 1, 2021, at 9:14 p.m., Farwell entered Birchmore's Canton residence with his face partially obscured by a face mask, according to a state police report. Security cameras recorded him leaving the building 29 minutes later, the report said.

Three days later, Birchmore's employer, Sharon Public Schools, asked police to check on her because she had not shown up for work. Attempts to reach her by phone were also unsuccessful, state police said.

Canton police found Birchmore's body in her bedroom and an ultrasound picture of her unborn baby in the kitchen.

Sean Cotter can be reached at [email protected]. Follow him @cotterreporterYou can reach Laura Crimaldi at [email protected]. Follow her @lauracrimaldi.