Judge Nancy Gertner On Mattapan Murders Trial

The Mattapan murders trial reached another critical moment Tuesday. A single juror continues to keep the entire jury from reaching an unanimous verdict in the last nine of 19 charges in the quadruple murder case.

Tuesday afternoon jurors returned to the courtroom with a question regarding the "reasonable doubt" standard used in criminal cases. Turns out, that standard dates back to an 1850 Massachusetts decision, Commonwealth v. Webster, that became the definition for reasonable doubt nationwide.

For more, we spoke with Nancy Gertner. She's a retired U.S. District Court judge and current professor at Harvard Law School. We asked Gertner to discuss what it's like when a judge is faced with the possibility that a juror simply doesn't understand what a key term means and what to expect as the case comes to a close.

Guest: