Dr. Marie Russell previously testified that the holes found in John O’Keefe’s hoodie and the wounds to his arm were from a dog.

Prosecutors are aiming to chip away at Dr. Marie Russell's credibility and keep her off the witness list for Karen Read's retrial.

Norfolk Superior Court Judge Beverly Cannone is sitting tight on deciding whether Karen Read’s defense can use its preferred dog bite expert in her second trial scheduled to begin in April. After yet another marathon hearing to determine the fate of Dr.