The Massachusetts POST Commission has decertified William Farwell, a former Stoughton Police officer and brother of Matthew Farwell, who the feds have charged with killing Sandra Birchmore.

“The Respondent William Farwell has entered into a Voluntary Decertification Agreement under which he has agreed to the permanent revocation of his certification (also known as decertification) as a law enforcement officer in the Commonwealth of Massachusetts,” a notice by the commission posted Tuesday states.

The agreement states that William Farwell agrees that should his case move to an adjudicatory hearing, the evidence against him is strong. It waives his right to appeal.

The commission’s discussion preceding the decertification is not known, as the commissioners who attended Tuesday morning’s virtual meeting voted unanimously to enter an executive session and not return to the public meeting.

The basics of the complaint against William Farwell are similar to those against his brother, minus impregnating and murdering Birchmore in her Canton apartment. He is accused of having an inappropriate relationship with Birchmore who he first met when as a child she entered the Stoughton Police Department’s Explorers Program to learn about being a police officer.

William Farwell worked at the Stoughton PD from March 21, 2017, until his resignation on Aug. 1, 2022, according to the decertification agreement.

An internal PD investigation opened on Nov. 22, 2022, concluded that William Farwell had lied about the extent of his relationship with Birchmore — who is identified throughout the document only under her initials, S.B.

William Farwell allegedly admitted that he had a sexual relationship with Birchmore for about two years. The investigation further claims that he exchanged sexually explicit texts with Birchmore while on duty. All of this allegedly took place while Birchmore was an adult. He also allegedly made around 26 unauthorized searches on the Criminal Justice Information Services databases on both himself and Birchmore.

Matthew Farwell

William Farwell’s brother Matthew Farwell was charged late last month with killing Sandra Birchmore, which prosecutors say he did as a way to cover up his crimes of raping her when she was underage beginning in 2015 and continuing their sexual encounters even while he was on duty. The inciting action, according to prosecutors, is when Birchmore revealed to the married father that she was pregnant with their child.

A month after that disclosure, prosecutors allege, Matthew Farwell on Feb. 1, 2021, went to Birchmore’s Canton apartment, strangled the 23-year-old to death and staged the scene to look like a suicide.

Stoughton PD Chief Donna McNamara said that the department put Matthew Farwell under administrative leave and launched an internal investigation later that same month when it first heard of the allegations. He submitted his resignation that April and was decertified by the POST Commission earlier this year.

Stoughton Police Department headquarter (Staff Photo By Matt Stone/MediaNews Group/Boston Herald)