A former Canton police lieutenant who was in charge of the scene of John O’Keefe’s death on Jan. 29, 2022, testified about his decision to use unorthodox evidence collection means that morning in the trial of Karen Read, a Massachusetts financial analyst accused of running over her boyfriend, a Boston police officer, and leaving him to die in the snow.

Last week saw days of testimony from Jennifer McCabe, a key witness who was present at the after-party on the night O’Keefe died and with Read at the scene when he was found dead the next morning.

Special prosecutor Hank Brennan churned through witnesses Monday, calling a blood-alcohol expert, a young couple who saw Read’s car outside before prosecutors believe O’Keefe was struck and killed, a paramedic and the former Canton cop who used a leaf blower and red Solo cups to collect evidence.

“He did not see John O’Keefe in the car or on the lawn or crossing the lawn,” said Grace Edwards, a Massachusetts defense attorney who has been following the trial. “So where was John O’Keefe?”

The question could boost the defense’s assertion that Read never struck her boyfriend with her SUV, according to John Deaton, another Massachusetts trial attorney and former Senate candidate.

“Today’s testimony hurts the prosecution, as a witness stated the passenger seat was empty next to Karen Read in the driver’s seat, suggesting that John O’Keefe was already inside the house,” he told Fox News Digital. “That’s probably reasonable doubt No. 10.”

Sarah Levinson, a friend of Nagel’s sister who was inside the house, testified that O’Keefe did not come into the home before she left between 1:30 and 2 a.m. with McCabe, her husband, Matt and Julie Nagel. 

Read faces charges of second-degree murder, manslaughter and fleeing the scene. She could face up to life in prison if convicted of the top charge.