Just 12 minutes into Matthew Farwell’s federal trial, the prosecution turned the jury’s attention to the State Police investigation into Sandra Birchmore’s death.
Detectives assigned to Norfolk District Attorney Michael W. Morrissey didn’t treat the Canton apartment where Birchmore was found as a crime scene, the prosecutor said. They made crude comments about having to investigate at all, with one saying they “needed an investigation like they, quote, ‘needed a [expletive] bullet in the head’,” the prosecution told jurors.
The criticism laid bare the unusual dynamics for a criminal trial: The refusal of state investigators to pursue a criminal case against Farwell — and the FBI’s reversal of that decision — which is now forcing federal prosecutors to both show not only that Farwell killed Birchmore, but also that state investigators got it wrong when they concluded Birchmore killed herself.
Jurors must decide: Which experts, investigators, and analysts to believe? How can prosecutors prove their case beyond a reasonable doubt after an earlier investigation concluded there was no crime?
“It is unusual that the prosecution, state and federal, would be at odds,” said Glenn MacKinlay, a partner at McCarter & English and former homicide prosecutor.
But, he added, federal authorities had no choice but to try to discredit state investigators “once they determined that there was a homicide committed here.”
State Police and a spokesperson for Morrissey declined to comment, citing the ongoing trial.
Troopers from Morrissey’s unit were also accused of bungling the investigation into the death of Boston police Officer John O’Keefe. Last year, a jury acquitted his girlfriend Karen Read of second-degree murder after she alleged that investigators mishandled the case.
In Birchmore’s case, Morrissey’s office had determined that she died by suicide, citing the initial state medical examiner’s finding. But federal prosecutors indicted Farwell in August 2024 on a charge that he killed Birchmore and staged her death to look like a suicide. (The state medical examiner now says her manner of death is undetermined.)
Assistant US Attorney Torey B. Cummings has told jurors that State Police closed their investigation into Birchmore’s death without seeking any search warrants or attending her autopsy. Police met separately with Farwell and his twin brother, William, for interviews, but they occurred in parking lots, and the investigators did not record the interviews or take notes, according to trial testimony.
“That’s too important an interview to be conducted on the fly like that,” MacKay said.
Victor Hansen, who teaches at New England Law Boston, said the prosecution is trying to “get ahead of what they anticipate will be one of the defense’s line of attacks.” If the defense argues that state investigators did not believe Farwell killed Birchmore, then prosecutors will argue that they were too deferential to fellow police officers.
“What they’re trying to do is paint a motive for the initial investigation to be flawed, that they were giving this guy a break. They didn’t want to go after one of their own and so they weren’t handling this case like they should have,” Hansen said.
Farwell, 40, has pleaded not guilty. The defense asserts that Birchmore killed herself after Farwell, a married father, broke up with her and denied paternity. DNA testing later excluded him as the father.
Early on in the trial, defense lawyer Joanne M. Daley accused prosecutors of trying to distance themselves from state authorities involved in the initial investigation, arguing that the FBI is relying on some of the evidence gathered by those same state investigators. Those officials still represent the government, the same government that brought the criminal prosecution against Farwell and the jury should be reminded of that, Daley argued.
But FBI Special Agent Heidi Kelsch gave the jury an overview of how federal authorities got involved on their own and addressed what they saw as gaps in the earlier investigation.
Birchmore’s death was referred to the FBI by a civilian and two police officers, including Brian Holmes, the former Stoughton police deputy chief who conducted an internal investigation examining the department’s contact with Birchmore, Kelsch said.
Initially, the FBI was trying to determine whether Farwell had used his police authority to deprive Birchmore of her constitutional rights by sexually abusing her, beginning when she was a 15-year-old Stoughton Police Explorer, Kelsch said.
The investigation then widened to look at whether Farwell killed Birchmore, she said.
Agents subpoenaed police reports, Birchmore’s medical and school records, and secured search warrants for her Facebook, Google, and iCloud data, as well as Farwell’s iCloud account and Google searches.
Federal investigators discovered about 40,000 messages between Birchmore and Farwell, many of which had not been examined by State Police, prosecutors wrote in court papers.
“I went line by line through hundreds of thousands of messages,” Kelsch testified.
In the texts, Birchmore and Farwell wrote about Birchmore missing school to meet him for sex, and they discussed conceiving a child, Kelsch testified.
She said she sought out other records to try to verify what she found in the texts. Agents interviewed about 130 witnesses and reviewed hundreds of pages of records, plus videos, photographs, and other evidence, she said.
Birchmore’s medical records showed she talked about being tutored by a police officer in March 2013 and asked about birth control in May 2013. That confirmed some of the text messages, including some about Farwell tutoring Birchmore at the library.
Other potential evidence was lost to time and missed opportunities, according to trial testimony.
State Police never sought any warrants in the case, and thereby missed the chance to search Farwell’s residence and vehicle soon after Birchmore’s body was found on Feb. 4, 2021, prosecutors have said. Farwell wasn’t asked to turn over any of the clothing he was seen wearing on surveillance video when he visited Birchmore’s apartment three days earlier.
Farwell also deleted his Facebook account and told investigators he had deleted all messages he exchanged with Birchmore after he left her Canton apartment on Feb. 1, 2021.
At the beginning of the trial, the prosecution asked State Police Trooper Matthew Dunne, an investigator from Morrissey’s office, specifically about steps he didn’t take in his investigation.
Dunne testified he didn’t interview Birchmore’s neighbors or notice that her flamingo pendant necklace had snapped along the chain. The prosecution has pointed to the broken chain as a sign that Birchmore struggled; her family later found it where her body had been discovered.
Dunne also told the jury that Farwell told him and another investigator that he started having sex with Birchmore in 2020 and had only done so two or three times.
He testified that State Police later learned from interviews and reviewing text messages that Farwell had lied about when he initiated sexual contact with Birchmore.
“Yes, we had information from interviews and cellphone data that it was much earlier than that,” Dunne told the jury.
Alan Tuerkheimer, a jury consultant in Chicago, said juries often assess the fairness and integrity of investigations, which the defense may challenge as biased.
With two investigations with opposing conclusions, he said the prosecution must be clear with the jury about why the federal government got involved and what its investigation found.
“As long as their prosecution comes off as sound and fair, and not trying to back into a result, I think jurors will understand that,” Tuerkheimer said. “If the jury questions the motivations or if they think the prosecution was unclean or sullied in any way, then that can certainly raise doubts about guilt beyond a reasonable doubt.”
Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her @lauracrimaldi. Sean Cotter can be reached at sean.cotter@globe.com. Follow him @cotterreporter.