Prosecutors allege Karen Read struck her boyfriend, John O'Keefe, with her Lexus SUV outside of a get-together at another officer's home and left him to die.

A key witness in the retrial of Karen Read returned to the stand Wednesday for a second day of testimony, as she recounts the hours leading up to the death of Read’s boyfriend John O’Keefe – and the moment the off-duty Boston police officer’s body was found lying in the snow.

Jennifer McCabe is set to take the witness stand in Karen Read's second murder trial. 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.