Jury deliberations began on Tuesday in the murder trial of Karen Read, who is accused of intentionally backing her vehicle into her boyfriend, a Boston police officer, and then leaving him to die in the snow outside a house party. The case has drawn outsize attention, fueled by her lawyers’ accusations of a police cover-up.

It has also transfixed Boston, where a devoted band of supporters who believe Ms. Read was framed have galvanized a “Free Karen Read” movement. Dressed in pink, they have gathered outside Norfolk County Superior Court whenever her trial is in session, picking apart the evidence and the web of relationships involved. A Boston blogger known as Turtleboy, who also supports Ms. Read, has been charged with harassing and intimidating witnesses.

What happened?

In January 2022, Ms. Read and her boyfriend, John O’Keefe, a 46-year-old Boston police officer, had been out drinking with friends in Canton, Mass., a town about 20 miles south of Boston. At a bar, they ran into another Boston police officer and were invited to a late-night party at his house.

Shortly after midnight, they drove to the house, where Officer O’Keefe got out of Ms. Read’s black Lexus S.U.V. Prosecutors say that the couple had been fighting and that Ms. Read accelerated in reverse, intentionally striking her boyfriend before leaving him in the snow.

He was found unresponsive later that morning by Ms. Read, who said she had frantically searched for him after waking up on his couch around 4 a.m. and realizing he had not come home. Officer O’Keefe, who had severe head injuries and hypothermia, was pronounced dead on Jan. 29, 2022.

Ms. Read was arrested three days later. She has pleaded not guilty to charges of second-degree murder and manslaughter.