Former Stoughton police detective Matthew Farwell was found guilty of killing Sandra Birchmore and her unborn child. 

Jurors reached their verdict on Tuesday after more than 15 hours of deliberation over three days. 

Prosecutors say Farwell strangled the 23-year-old in her Canton apartment in 2021 and staged her death to look like a suicide.  They say he killed her to conceal crimes including sexually exploiting her as a teenager. 

Farwell remains in federal custody ahead of sentencing.