Boston, Massachusetts - Former Stoughton police officer Matthew Farwell is on trial for the 2021 death of 23-year-old Sandra Birchmore and the death of her unborn baby. But as a federal jury deliberates to reach a verdict, the core question reaches beyond his guilt: did local police cover up her death to protect one of their own, forcing the FBI to step in?

The federal case traces back to when Birchmore was 13 years old and joined the Stoughton Police Explorers, a youth program intended to foster interest in law enforcement careers. Federal prosecutors allege that Farwell, her then-27-year-old police instructor, began sexually abusing her when she turned 15, initiating an illicit, years-long relationship.

By late 2020, Birchmore became pregnant and allegedly gave Farwell an ultimatum, demanding he stay with her or risk having the affair exposed to his wife, the Stoughton Police Department, and federal authorities. Prosecutors are arguing that to protect his marriage, job, and freedom, Farwell strangled Birchmore in her Canton, Massachusetts apartment on February 1, 2021, and staged the scene to look like a hanging.

The federal charges Farwell faces are interesting by nature, and the case has captivated the nation for that reason. Because Farwell was never charged with murder in 2021 when Birchmore's body was found at the local or state level, things are handled slightly differently at the federal level.

Under standard state law, a local District Attorney prosecutes murder. However, because Massachusetts state and local authorities initially accepted her death as a suicide, state murder charges were never filed. To bring murder charges at the federal level, prosecutors invoked 18 U.S.C. § 1512(a)(1)(C) – a statute specifically prohibiting killing a witness, victim, or informant. He is charged with killing a witness or victim, and with causing the death of an unborn child.

The reason federal prosecutors got involved relates to how local authorities handled Birchmore's death in February 2021.

During trial proceedings, including witness cross-examinations of the original state troopers, federal investigators described the initial response by local authorities as rushed and severely compromised. They argued that the police, possibly in an effort to protect Farwell and themselves, treated what they believe was an obvious crime scene as an open-and-shut suicide without verifying the information.

State police admitted during the trial to have interviewed Farwell for roughly 15 minutes in a parking lot, and no written notes were taken, and no audio or video recordings were taken, either. They also failed to collect any physical DNA evidence and did not seize Farwell's phone until days later, which they argued may have allowed texts between Farwell and Birchmore to be deleted. Federal investigators were later able to recover deleted digital data.

The state medical examiner initially ruled the case a suicide, based on the limited information they were provided by local police who were at the scene. When federal medical experts got involved and looked at the evidence, they found that Birchmore's injuries, which included neck trauma and a fractured hyoid bone, were inconsistent with a self-inflicted hanging.

It was then that the state medical examiner's office decided to formally withdraw its suicide finding, ruling the cause of death as "undetermined."

While federal prosecutors painted the picture of a murder scene staged to look like a suicide, the defense presented a different argument to the eight-man, four-woman federal jury, which is currently deliberating for the second day.

Defense attorneys argued that Farwell went to Birchmore’s apartment on February 1, 2021, to end their secret relationship. His defense attorney, Kimberly Stevens, spoke of Birchmore’s documented mental health struggles and past references to suicide in her journal.

"When all is lost in life, and all hope is gone, and you're alone in the world ... did she sit down and take that strap ... and make the pain stop?" Stevens asked jurors during closing arguments on Friday.

As the jury continues to deliberate on Monday in a Boston federal court, the verdict remains suspended in the balance. Also on Monday, Farwell's defense team reportedly filed a motion for acquittal, per a post on X by LA Mag's senior editor @MicheleMcPhee.

If the jury convicts Farwell, it will confirm that a federal probe was necessary to break through local silence to secure justice for Birchmore and her unborn child. If acquitted, it may leave the local community in Canton questioning whether police negligence in 2021 compromised the truth forever.