The twin brother of Matthew Farwell will be back on the stand Tuesday when court gets underway in the trial of Matthew Farwell.
Farwell is accused of killing Sandra Birchmore and her unborn baby.
William Farwell revealed Monday that he agreed to testify under the grant of immunity so his statements cannot be used against him.
William has only been on the stand for under 20 minutes.
[ Matthew Farwell trial: Farwell’s brother takes the stand ]
In that time, he admitted to having a sexual relationship with Sandra Birchmore when she was of legal age.
He said he did so while on duty as a Stoughton Police officer.
William Farwell said he met Birchmore when she was 20 or 21, in the summer of 2018, and their consensual relationship began then.
Farwell said at that time he did not know anything about his brother Matthew Farwell’s sexual relationship with Birchmore.
Jurors didn’t hear much more from William Farwell before court wrapped for the day.
Most of Monday’s testimony came from the medical examiner in the case.
Doctor Maria Del Mar Capo Martinez performed Sandra Birchmore’s autopsy.
Jurors saw those images on Monday.
Doctor Capo Martinez wrote her opinion on Sandra Birchmore’s cause of death to be asphyxia by hanging and the manner of death to be suicide on May 6, 2021.
The doctor said before making that opinion she only had an intake form indicating no signs of trauma, a report from Massachusetts State Police, and an email exchange with law enforcement.
But Capo Martinez testified Monday to having no information about Birchmore’s phone being found near her hand, when that phone sent its final text or when it was locked, the content of texts on that phone, the surveillance video from the apartment on Feb. 1 2021, visitor’s to Birchmore’s, consensual choking between Birchmore and anyone who visited her, and witness statements.
She only knew Birchmore was suspected to be pregnant.
“I was not asked to consider whether this was a homicide,” said Dr. Capo Martinez.
The prosecution asked what she may have done differently if she had been asked that.
Dr. Capo Martinez said, “Probably the processing of the body and the collection of the evidence.”
The doctor said new information came to light and the cause of death was changed only to asphyxia with the manner being undetermined.
The doctor explained to jurors that undetermined is used when there may be multiple manners of death considered and can’t be excluded.
The prosecution asked, “Who if anybody pressured you to change the death certificate?”
“I was not pressured to change the death certificate,” said Capo Martinez.
The defense brought up that Doctor Capo Martinez met with the FBI and US District Attorneys Office in 2024.
A forensic expert shared a different opinion of what happened to Sandra Birchmore with Capo Martinez at that meeting.
In Spring 2026, more than five years after Birchmore’s death, Capo Martinez changed Birchmore’s death certificate.
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