Karen Read’s defense called its first witness on Friday, marking a new phase in her retrial in the killing of John O’Keefe, her off-duty Boston police officer boyfriend whose body was found buried in the snow outside a home in Canton,

The defense in Karen Read’s murder retrial took center stage Friday when they called their first witness to the stand after the prosecution rested its case late Thursday morning.‘There was no collision’: Defense asks judge to stop Karen Read’s retrial,