Prosecutors in the Karen Read case are asking a judge to exclude a defense dog bite expert from testifying at her upcoming retrial. 

Read is charged with second degree murder over the 2022 death of her Boston cop boyfriend John O'Keefe in Canton. 

Her first trial ended in a mistrial in July, and the retrial remains scheduled for late January despite requests from both sides to delay it until April. 

Prosecutor Hank Brennan says the defense failed to prove that longtime emergency room doctor Marie Russell of California is a qualified expert, despite her testifying at the first trial.