Sandra Birchmore was 23 and pregnant when she was found dead in her Canton apartment. Federal prosecutors say former Stoughton detective Matthew Farwell changed his behavior toward her shortly before her death, then arrived at her building wearing a hood and medical mask. The defense maintains Sandra died by suicide. A friend had called the Stoughton Police Department to disclose the relationship between Sandra and Farwell. Assistant U.S. Attorney Torey Cummings told jurors that Farwell initially reacted with anger. But Sandra subsequently described what prosecutors call a complete 180. He was being nice again and had asked for a key to her apartment. Prosecutors argue he was trying to make her feel safe before killing her. Farwell has pleaded not guilty. Robin Dreeke, a retired FBI behavioral expert, examines that alleged shift. Why would an investigator look closely at a sudden change in behavior? How much can a hood, a mask, and a security-camera recording tell us without presuming what happened inside the apartment? The investigation itself deserves scrutiny. Prosecutors criticized the Massachusetts State Police response and the failure to pursue important steps early on. The state medical examiner originally classified Sandra’s death as suicide, then changed her manner of death to undetermined in April 2026. Dr. Michael Baden, retained by the family, concluded that Sandra was strangled, while Farwell’s lawyers dispute the homicide allegation. The federal jury must evaluate those competing accounts. The wider question is how a death investigation reached its first conclusion and why later investigators saw a different picture. Sandra’s family has spent years seeking answers, and the decisions made after she was found are now part of the story. Listen Anywhere You Get Podcasts: https://pod.link/1655749292 Want to comment and watch this podcast as a video? Check out our YouTube Channel. https://www.youtube.com/@hiddenkillerspod?sub_confirmation=1 Join Our SubStack For AD-FREE ADVANCE EPISODES & EXTRAS!: https://hiddenkillers.substack.com/ Watch Robin Dreeke's MasterClass: http://masterclass.com/robindreeke Instagram https://www.instagram.com/hiddenkillerspod/ Facebook https://www.facebook.com/hiddenkillerspod/ Tik-Tok https://www.tiktok.com/@hiddenkillerspod X Twitter https://x.com/tonybpod This publication contains commentary and opinion based on publicly available information. All individuals are presumed innocent until proven guilty in a court of law. Nothing published here should be taken as a statement of fact, health or legal advice. #SandraBirchmore #MatthewFarwell #HiddenKillers #FarwellTrial #StoughtonPolice #RobinDreeke #MassachusettsStatePolice #MichaelBaden #JusticeForSandra #truecrimecommunity