A Massachusetts District Attorney whose office is prosecuting a woman for the murder of her Boston police officer boyfriend has come under fire for dismissing recent conspiracy theories surrounding the case.

Karen Read, 42, is accused of hitting John O’Keefe with her SUV in January 2022 and leaving him to die in the snow. Her defence team claims someone else killed him at the house after she dropped him off and have accused local and state enforcement of a massive coverup.

The case has gained nationwide media coverage in recent weeks sparking a slew of conspiracy theories online and alleged harassment of the prosecution’s witnesses.

“The harassment of witnesses in the murder prosecution of Karen Read is absolutely baseless. It should be an outrage to any decent person, and it needs to stop,” Norfolk County District Attorney Michael Morrissey said in a video statement on Friday.

“Innuendo is not evidence. False narratives are not evidence,” he continued.

Mr Morrissey defended several of the prosecution witnesses including police officer Brian Albert, who owns the home where O’Keefe died.

“These people were not part of a conspiracy and … have not engaged in any cover up,” Mr Morrissey said. “To have them accused of murder is outrageous. To have them harassed and intimidated based on false narratives and accusations is wrong. They are witnesses doing what our justice system asks of them.”

He also came to the defense of Mr Albert’s 18-year-old nephew, Colin Albert, who has been accused by some people online of attacking O’Keefe when he reportedly entered the home that night.

But Mr Morrissey, however, claimed O’Keefe never went inside the house.

“But phone evidence shows O’Keefe never entered the home at all,” Morrissey claimed in the video.

“Testimony from witnesses tell us that 18-year-old Colin Albert had left his uncle’s home before John O’Keefe and Karen Read had arrived outside the residence. There was no fight inside that home. John O’Keefe did not enter the home. Colin Albert, the young man being vilified, was not present when Read’s vehicle and John O’Keefe arrived on the street. This is a false narrative. Colin Albert didn’t commit murder.”

Michael Proctor, a state police trooper who has been accused of planting evidence outside the house, was another witness defended by Mr Morrissey.

He said Proctor “was never at Fairview Road on the day of the incident” and that the officer would have no motive to do so given that “he had no close personal relationship with any of the parties involved in the investigation and had no conflict.”

The video statement was issued following reported criticism online, though Mr Morrissey did not call out anyone in the video.

Just days before the statement was issued, an episode of the popular podcast “Turtleboy Live,” hosted by Aidan Kearney, slammed a former FBI agent turned crime commentator for defending the Albert and McCabe families in posts on X, formerly Twitter.

Read’s attorneys claim O’Keefe’s injuries were consistent with a severe beating, rather than being struck by a car, and that Ms Read is being framed by the real killer or killers.

The case hit headlines again in late July 2023 as Ms Read appeared in a Dateline interview, where she insisted she and O’Keefe were “happy, having fun, laughing” in the hours before he was killed and alleged she is being unfairly prosecuted in a “cover-up”.

“The idea that multiple police department EMTs, fire personnel, medical examiner and prosecuting agencies have joined in and taken in a vast conspiracy should be seen for what it is – completely contrary to the evidence and a desperate attempt to reassign guilt,” Mr Morrissey later said in the video statement.

He said the rare video statement was released instead of holding a press conference because his “remarks need to be so narrowly tailored to the issue at hand while the prosecution is pending in superior court.”

“A grand jury of every day citizens heard the documented evidence and testimony before making a decision. The subject of that murder indictment enjoys the constitutional presumption of innocence. Why should the witnesses who have committed no crime be afforded less by members of the community?” Mr Morrissey said.

“They should not be harassed for telling the government what they heard or saw. I’m asking the Canton community and everyone that feels invested in this case to hear all the actual evidence at trial before assigning guilt to people who have done nothing wrong. And certainly before taking it upon yourself to harass citizens who evidence shows have done nothing in this matter but come forward and be a witness.”

“What is happening to the witnesses, some with no actual involvement in the case, is wrong. It is contrary to the American value of fairness, and the Constitutional value of a fair trial,” he added.

“What is happening to these innocent people, these witnesses, is wrong, and it needs to stop.”

Mr Morrissey’s video statement on Friday, which was an uncommon move by a DA, was scrutinized by many people online.

“I agree that statement Morrissey made is just made everything 10x worse for the Proctors, Lanks, and Alberts,” one person commented, asking “Whose terrible idea was that?”

Another Twitter user pointed out the oddity of a DA making such a statement outside of court.

“Can anyone remind me why the FBI is involved? Also, has a DA ever done this before?”

Online commenters also slammed the DA for putting out information that appeared to differ from what has already been reported.

“The DA either lied or was incorrect in multiple statements. We shall learn more, during trial.”