Massachusetts State Police Trooper Joe Paul, who was just about to offer his analysis of a critical piece of evidence in the Karen Read murder trial when testimony ended Friday, is expected back on the stand when the trial resumes this morning.

Paul is a collision specialist and crash reconstructionist for the agency. He had testified on tests he performed on Read’s Lexus SUV, which prosecutors say the Mansfield woman used to run down Boston Police Officer John O’Keefe after midnight on Jan. 29, 2022, following an evening in which the couple drank heavily, and leaving his body in the front yard of the Canton home of a fellow Boston cop who was hosting an after-party.

He said he reconstructed the data Read’s Lexus had recorded that shows the vehicle “going straight, it stops, goes into reverse.” He said the vehicle reversed 62 ½ feet and hit 24 mph before coming to a stop. That stop, he said, is when the vehicle struck O’Keefe in a “sideswipe manner”

He said further that O’Keefe would have been struck on his right side “and he would have been spun out … projected to the left,” meaning that he would have been out of the way of the vehicle after the initial hit and thus not further run over as people would be if struck in the center of their mass.

“With the lacerations from the arm, to the taillight, the dent for the scratches where his hand could be. Those would be something that would be consistent, in this particular case, with striking the Lexus,” Paul said.

Perhaps the most intense part of Paul’s testimony came after jurors were dismissed for the day at 3:50 p.m. It was then that defense attorney Alan Jackson became worked up about a bit of evidence prosecutor Adam Lally brought up before Jackson objected and called for a sidebar.

Jackson said that Lally had given the defense no notice he would question Paul about another piece of evidence to the defense’s theory of the case: that Read had broken her taillight not by striking O’Keefe himself but by striking his parked Chevrolet Traverse SUV while backing out of his garage at around 5 a.m. that early morning to set out in search for him.

Paul said after the jury was gone that he had seen the Ring camera footage from outside O’Keefe’s garage where, as Lally put it, “either comes close to or makes contact with O’Keefe’s vehicle.” Paul said he had and further said he saw no damage to O’Keefe’s Traverse that would indicate Read had struck it.

“Did you ever put the two cars together?” Jackson asked, quite apparently upset, before motioning to have the evidence excluded. “You didn’t test whether the right rear lens could have matched up with any point of the traverse?”

This is a developing story.