A medical examiner testified she could identify John O’Keefe’s cause of death as a head injury and hypothermia but could not determine whether it was homicide, accidental or any other manner Thursday during the murder trial of Karen Read in the 2022 death of her boyfriend, a 46-year-old Boston police officer.

Dr. Irini Scordi-Bello, a forensic pathologist with Massachusetts’ Office of the Chief Medical Examiner, performed the autopsy on O’Keefe Jan. 31, 2022.

While Scordi-Bello found that O’Keefe had died from head trauma and hypothermia, the manner of death — how he suffered those injuries — was undetermined.

The blunt impact to his head was the primary cause of death, she testified, but hypothermia contributed. He had a deep cut and bruising to the back of his head. Once she looked at it from the inside, she found multiple skull fractures and brain bleeding. And his body temperature when he arrived at the hospital was 80.1 degrees compared to a normal body temperature of 98.6.

After Judge Beverly Cannone sent jurors home for the day, Alessi argued that new disclosures about expert testimony from Aperture, which conducted reports for the prosecution, would put the “entire defense” at risk if allowed this late in the game.

The disclosure was dated May 8 but was received by the defense May 11, he said.

Karen Read listens to the testimony of Jennifer McCabe during Read’s murder trial in Norfolk Superior Court in Dedham, Mass., Wednesday, April 30, 2025.  (Greg Derr/The Patriot Ledger via AP, Pool)

“I don’t like to use hyperbolic words, but the word has been used against us — ambush, ambush, ambush,” Alessi said. “If there’s ever an example of an ambush, this is it.”

In a heated back and forth, Brennan described the disclosure as evidence of a significant variance between the internal clocks in Read’s Lexus SUV and John O’Keefe’s cellphone data.

Cannone did not announce a decision before adjourning court for the day.

Read is due back Friday at 9 a.m.

She could face life in prison if convicted of the most serious charge.