Karen Read pleaded not guilty to murder charges in the death of Boston police officer John O’Keefe and is facing a retrial after a jury was unable to reach a verdict last year.

Witness testimony continued in the murder retrial of Karen Read Wednesday after Judge Beverly Cannone asked to speak with each juror individually.

The conclusions of the medical examiner who performed John O’Keefe’s autopsy left more questions than answers, which both the prosecution and Karen Read’s defense team seized on to promote

The prosecution in Karen Read's retrial laid out a critical component of its case during the fourth week of testimony.

A prosecution expert testified Monday in the Karen Read retrial that Read's SUV was backing up at the same moment her boyfriend, Boston police officer John O'Keefe, last used his cellphone.

According to our Boston affiliate WCVB, the tail light DNA came from three separate people, including at least one male. The sample was a “strong match” for Boston police officer, John O’Keefe. Bradford explained the hair sample found in the back of the SUV did not give enough DNA to identify it.