The lead investigator in the case of a woman accused of leaving her Boston police officer boyfriend for dead in a snowbank has come under fire for a series of offensive and inappropriate texts he wrote about the defendant during the investigation.

Massachusetts State Trooper Michael Proctor, who took the stand Monday and will continue to be cross-examined Wednesday, acknowledged to the jury that he called Karen Read a series of names including “wack job” in texts to friends, family and fellow troopers. He also joked about a medical condition she had in some of those text exchanges and said that he believed she was responsible for killing John O’Keefe.

The testimony came in the seventh week of trial for Read, who has pleaded not guilty to second-degree murder in the January 2022 death of O’Keefe. Prosecutors say Read dropped O’Keefe off at the home of a fellow officer after a night of drinking and struck him while making a three-point turn. They say she then drove away. Her defense team argues that she has been framed.

Proctor repeatedly apologized Monday for the language used in the text exchanges and acknowledged they were “unprofessional and regrettable comments are something I am not proud and I shouldn’t have wrote in private or any type of setting.”

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But he insisted the comments had no influence on the investigation.

“These juvenile, unprofessional comments had zero impact on the facts and evidence and integrity of the investigation,” Proctor told the court.

The defense team jumped on the exchanges including one where Proctor also wrote that he hated one of Read’s attorneys. They also noted a text in which Proctor joked to his supervisors about not finding nude photos when he was going through Read’s phone.

Proctor denied he was looking for nude photos of Read, though her defense attorney Alan Jackson suggested his response demonstrated bias in the investigation.

“You weren’t so much as objectively investigating her as objectifying her in those moments,” Jackson said.

The text exchanges could raise doubts with the jury about Proctor’s credibility and play into the hands of the defense which has questioned law enforcement’s handling of the investigation.

Read’s lawyers have alleged that O’Keefe was beaten inside the home, bitten by a family dog and then left outside.

They have portrayed the investigation as shoddy and undermined by the relationship investigators had with the law enforcement agents at the house party. They also have suggested pieces of glass found on the bumper of Read’s SUV and a hair found on the vehicle’s exterior may have been planted.

Proctor acknowledged Monday that he is friends with the brother of Brian Albert and his wife — though he insisted it had no influence on the investigation and had never been to their house before O’Keefe’s death. Brian Albert is a Boston police officer, whose hosted the house party where O’Keefe’s body was found in the front yard.

His text exchanges could also distract from evidence he and other state troopers found at the crime scene, including pieces of a clear and red plastic found at the scene in the days and weeks after O’Keefe’s body death. Proctor held up several evidence bags Monday that prosecutors said contained pieces of plastic collected from the crime scene.

Prosecutors argue that the pieces are from the broken taillight on Read’s SUV, which she damaged when she hit O’Keefe. They also produced video evidence Monday refuting defense claims that Read backed into O’Keefe’s car and damaged the taillight. Proctor also testified that he found no damage on O’Keefe’s car nor the garage door.