BOSTON (WHDH) - In a day of technical and dense testimony, Matthew Farwell’s defense team called two forensic experts to the stand Tuesday to answer questions related to how evidence in the murder case was collected, tested, and analyzed.
The defense first called forensic DNA expert Dr. Maher Noureddine to the stand to raise questions about whether evidence in the death of Sandra Birchmore was contaminated in the way it was transported to the Massachusetts State Police lab.
His testimony also reviewed the Massachusetts State Police’s DNA analysis of multiple swabs from Birchmore. There was much discussion over the complexity of the results, because DNA from multiple men was found.
Noureddine questioned some of the types of tests and the methodology of the state lab. He testified, “I take issue with the interpretation of that mixture,” adding, “My critique is that the lab interpreted a mixture they should not have.”
Another issue raised was the similarities in DNA between the Farwell brothers. Matthew Farwell’s twin, William Farwell, previously testified that he also had a sexual relationship with Birchmore. The lab did not test William’s DNA, something Noureddine said could impact the results.
Farwell is charged with killing 23-year-old Birchmore and her unborn child and staging the death to look like a suicide. Her body was found in a seated position with a strap around her neck and tied to a doorknob. Prosecutors allege Farwell killed her to stop her from exposing federal crimes, including sexual exploitation of a child. They claim Farwell had been grooming her for sex since she was 15-years-old and part of the Stoughton Police Explorers mentoring program.
Farwell’s defense maintains Birchmore took her own life.
The second witness Tuesday was former FBI Forensic Anthropologist Dr. Angi Christensen, who examined Birchmore’s fractured hyoid bone. The U-shaped neck bone has been a central piece in the case.
The prosecution argues that the type of fracture she suffered is not common in suicides, or in younger individuals, suggesting it is more common in strangulations.
Christensen testified that “no established force…is required” to cause a fracture, but agreed that “hyoid bone fractures are less common in younger individuals.”
Another full day of testimony is expected Wednesday as two more witnesses take the stand. Jury deliberations are expected to begin Friday.
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