Dateline NBC “The Betrayal of Sandra Birchmore” September 19 2025 Recap & Preview
Dateline NBC continues its commitment to in-depth investigative reporting with a haunting new episode, The Betrayal of Sandra Birchmore, airing Friday, September 19, 2025, at 10/9c. Andrea Canning reports on a case that shook Massachusetts and reignited national conversations about grooming, law enforcement misconduct, and accountability.
Sandra Birchmore was just 23 years old when she was found dead in her Canton, Massachusetts apartment on February 4, 2021. At first, her death was ruled a suicide by asphyxia. But years later, a federal investigation concluded what her family had long believed — that Sandra’s death was not self-inflicted, but rather a homicide staged to look like suicide. At the center of the investigation: local police officer Matthew Farwell, who first met Sandra when she was only 12 and he was a 25-year-old officer involved in the Stoughton Police Explorers youth program.
Sandra’s life appeared to be on the rise. She worked as a teacher’s assistant, was taking nursing courses, and had recently learned she was pregnant. She believed the father was Matthew Farwell, with whom she had been in a long-running, secretive relationship. That relationship, federal prosecutors allege, began when Sandra was just a teenager. Despite marrying someone else, Farwell is accused of maintaining the inappropriate and abusive relationship for nearly a decade.
After Sandra’s death, her family pushed back against claims she was suicidal. They filed a wrongful death lawsuit against Farwell, his twin brother William, and their former supervisor. It wasn’t until 2024 that federal investigators ruled Sandra’s death a homicide, asserting that Farwell strangled her to cover up their relationship and her pregnancy. He was federally indicted for murder in August 2024.
Canning’s report features interviews with Sandra’s family, including her mother Lisa and siblings Erin and Tyler, as well as law enforcement officials involved in the evolving investigation. The episode explores the surveillance footage that showed Farwell entering Sandra’s apartment the night she died and the troubling history that led to the fatal encounter. It also touches on comparisons to other controversial cases in Norfolk County, including the recent Karen Read trial.
The Betrayal of Sandra Birchmore is a heartbreaking look at a young woman’s life, the people who failed her, and the family still fighting for justice. Watch the full episode Friday night on NBC, with streaming available the next day on Peacock.
