Jurors in Karen Read’s second murder trial heard more testimony Tuesday about location and temperature data recorded on her boyfriend’s cellphone the night she’s accused of killing him.

Prosecutors say Read, 45, backed her SUV into Boston police Officer John O’Keefe, 46, after dropping him off at a party hosted by a fellow officer in January 2022 and left him to die in the snow. Defense attorneys say she was a victim of a conspiracy involving the police and have suggested he was killed by someone inside the home.

A mistrial was declared last year after jurors said they were at an impasse. Read’s second trial on charges of second-degree murder, manslaughter and leaving the scene, began April 22 and has thus far looked similar to the first.

Did O’Keefe enter the house?

Digital forensics specialist Ian Whiffin testified Monday that location data on O’Keefe’s phone was consistent with the device being near a flagpole on the lawn of the home from 12:32 a.m. onward, there was no activity after that and the temperature of the phone’s battery dropped from 72 degrees (22 degrees Celsius) at 12:37 a.m. to 37 degrees (2.8 degrees Celsius) at 6:14 a.m.

Such data could suggest O’Keefe remained outside. But under cross-examination Tuesday, Whiffin testified that he observed a much more dramatic drop in temperature when he performed an experiment by placing a phone in a freezer.

He also acknowledged that the phone could have been anywhere within a larger radius than he previously described but said that data was not as accurate.

“According to your report, the phone of John O’Keefe could be in the house, correct?” defense attorney Robert Alessi asked.

“Based on the low-accuracy information, yes,” he said.

Timing of Google search in dispute

Whiffin, a former law enforcement officer who went on to work in mobile forensics in the private sector, also testified further about an internet search made by Jennifer McCabe, who was with Read the morning she found O’Keefe in the snow.

McCabe made a much-discussed web search about how long it takes to die in the cold. Read’s lawyers have said the search happened hours before O’Keefe was discovered, which could implicate her rather than Read. McCabe has said she made the search later at Read’s insistence after they found O’Keefe.

Whiffin said Monday that the web search was not made at 2:27 a.m., before O’Keefe’s body was found, like the defense has alleged. On Tuesday, he acknowledged that another company’s analysis showed the search happened at the earlier time.

The Supreme Court declines to get involved

The U.S. Supreme Court rejected Read’s double jeopardy appeal Monday, effectively clearing the way for her trial to continue.

Read’s defense had argued that putting her on trial again for two of the charges is an unlawful case of double jeopardy. They told the Supreme Court that the jury at her first trial reached a unanimous but unannounced verdict acquitting her, so a second trial on those charges should be barred as double jeopardy.

The court didn’t ask the prosecution to respond to the appeal, a sign the justices did not think there was a difficult legal issue at stake.

Jurors view crime scene

On Friday, jurors traveled to Canton, where O’Keefe was found outside the home of Brian Albert on Jan. 29, 2022. Read’s SUV was also parked there for the viewing.

Prosecutor Hank Brennan told jurors to view the scene from different vantage points and reminded them that it would have looked different at night, during a snowstorm. Defense attorney David Yannetti asked jurors to consider the distance between the home’s windows and doors and the front lawn. Jurors also should take a good look at Read’s vehicle, he said.

“Size it up,” he said. “Take it in.”