Massachusetts cop Matthew Farwell charged with strangling murder of pregnant woman Sandra Birchmore

A Massachusetts police detective has been charged with strangling a pregnant woman and framing her death as suicide in a bid to prevent her from revealing the extent of their relationship.

Matthew Farwell, 38, is accused of killing 23-year-old Sandra Birchmore within weeks of her telling him she was pregnant with his child. 

Police allege Farwell embarked on a sexual relationship with Birchmore when she was just 15. He would have been 30 at the time.

The federal indictment, seen by DailyMail.com, accuses Farwell of beginning that relationship when he was an instructor for the Stoughton Police Department’s Explorer’s Program, which was dedicated to teaching young people about careers within law enforcement.

Birchmore joined the program in 2010, when she was 12.

Police allege Farwell was motivated to kill her in order to prevent her from speaking out about the relationship.

Acting U.S. Attorney Joshua Levy on Wednesday said: 'Sandra Birchmore survived years of grooming, statutory rape and then sexual violence, all at the hands of Matthew Farwell, who was employed throughout the relationship as an officer and then detective for the Stoughton Police Department.'

The former cop was arrested by an FBI SWAT team on Wednesday morning and federally indicted a short time later.

The 23-year-old Birchmore was three months pregnant when she was found dead inside her home in 2021.

Her death was initially believed to be a suicide, but a pathologist who was hired by her family disagreed with that assessment and argued that she had been murdered. 

Police now allege Farwell 'staged her body and apartment to make it appear as if Birchmore committed suicide.'

'Farwell allegedly used his authority and access to groom, sexually exploit and ultimately sexually abuse Birchmore when she was 15 years old and continued to have sex with her when she became an adult,' the US Attorney's Office said in a statement.

In the statement, Farwell is accused of engaging in 'sex acts with Birchmore while on duty as a Stoughton police officer.'

'To conceal this activity, it is alleged that Farwell falsely represented that he had worked certain hours, when in fact he was not working but engaging in sex acts with the then-minor victim.

'Farwell’s sexual contact with Birchmore continued until her death on Feb. 1, 2021,' the statement reads. 

Police claim Birchmore had told loved ones prior to her death that Farwell 'became violent' when she revealed she was pregnant with his child.

The police statement said: 'At one point while she was pregnant, Farwell allegedly held Birchmore in a headlock and told her that he wished she were dead.'

Police claim Birchmore's friend called the Stoughton Police Department on January 20 and referenced the sexual relationship between the 23-year-old and Farwell.

Farwell was allegedly outraged and sent furious text messages to Birchmore and, several days later, asked her to provide him a key to her apartment - and to keep it a secret.

Police allege Birchmore became increasingly uncomfortable with Farwell's actions, making Farwell increasingly suspicious that she planned to disclose the nature of their relationship. 

More to come.