The new prosecutor in the upcoming retrial of Karen Read wants to exclude the defense’s expert on dog bites.

“I believe that these injuries were sustained by an animal. Perhaps a large dog,” Dr. Marie Russell testified as one of the defense’s first witnesses in Read’s first trial earlier this year.

Read, 44, of Mansfield, is charged with second-degree murder, motor vehicle manslaughter while operating under the influence, and leaving the scene of an accident causing death in the killing of her boyfriend of roughly two years, Boston Police Officer John O’Keefe, in the early morning of Jan. 29, 2022. Prosecutors say she rammed O’Keefe with her SUV and left him to freeze and die on the front lawn of 34 Fairview Road in Canton.

Her defense team has theorized that O’Keefe was killed by others within the home at that address. They’ve said they have phone movement data that places him inside the home and that the homeowner, fellow Boston cop Brian Albert, had a dog named Chloe that could have participated in the attack on O’Keefe.

A trial on the charges ended July 1 in mistrial due to a hung jury. A new trial is scheduled for Jan. 27, but both sides want Judge Beverly Cannone to push it back to April.

Russell, a retired emergency room doctor who last performed an autopsy in 1995, testified on the stand in June the she has written multiple peer-reviewed articles on the subject of dog bites, saying that “I have a strong interest in wounds in general, and I have a strong interest in dog bites in particular,” she said, adding she could have treated 500-1,000 people with such injuries.

But Hank Brennan, who was assigned as a special prosecutor in the case after the first trial ended, says that the defense team has “failed to prove that Dr. Russell is a qualified expert in the field of canine bites or claw marks, veterinary medical science, forensic odontology, or canine behaviors” and that her testimony “cannot be reliably applied to facts.”

For that reason and others, he wrote in a motion filed Tuesday, Russell should be excluded from the stand. He first discussed excluding her at a hearing last month, after which Judge Cannone scheduled a hearing on the matter for Dec. 12

He further argued that the defense thrust the witness into the trial very late, after his fellow prosecutor Adam Lally had already called more than 50 witnesses. After receiving a brief summary of Russell’s bona fides that late in the game, Brennan wrote, prosecutors moved to have her excluded then “for the failure to comply with reciprocal and expert discovery.”

He adds that “most of Dr. Russell’s canine experience was from 28 years ago and focused on law enforcement canines … During her trial testimony, Dr. Russell conceded there was no law enforcement canine involved and, in her experience, a bite and hold injury that law enforcement canines are trained to do would appear different than a domestic canine and arguably vastly different from the victim’s minor abrasions, which were isolated to one area of his forearm.”

“The Commonwealth moves that this Court reconsider its findings that Dr. Russell was qualified to render an opinion in the defendant’s first trial and that the methodology or theory underlying her opinion, particularly without any corroborating evidence, was reliable,” Brennan wrote in the motion. “An expert witness is not permitted to testify to matters beyond an area of expertise or competence.”

Dr. Marie Russell testifies during the murder trial of Karen Read at Norfolk Superior Court in June. (Staff Photo By Stuart Cahill/Boston Herald)