Trial of Ex-Cop Accused of Killing Pregnant Woman Begins

• Sandra Birchmore, a 23-year-old pregnant woman, was allegedly killed by ex-cop Matthew Farwell.
• A close friend of Birchmore testified that she had asked police to investigate Farwell after Birchmore's mysterious death.
• An ultrasound of Birchmore's unborn son was presented as evidence in the trial against Farwell.
• Farwell is accused of killing Birchmore to silence her about their affair and her pregnancy.
• The trial is taking place in Canton, Massachusetts.