Testimony resumed on Thursday in the retrial of Karen Read, a woman charged with murder in the death of her Boston police officer boyfriend, John O’Keefe, in 2022.
An accident reconstructionist, Dr. Judson Welcher, continued to face cross-examination about his analysis of Read’s vehicle and injuries to O’Keefe.
People to know:
Dr. Judson Welcher, an accident reconstructionist and biomedical engineer/prosecution witness Robert Alessi, defense attorney for ReadJudge Beverly Cannone
11:52 a.m. – Jurors sent home
Jurors returned to the courtroom, and the judge said, “We are ahead of schedule.”
She sent the jurors home and told them to come back on Friday at 9:30 a.m. because she first needs to discuss matters with lawyers in the morning.
Cannone told jurors to expect a full day.
11:28 a.m. – Prosecution rests its case
On re-direct questioning of Welcher, Brennan asked about the two Ring security cameras used from O’Keefe’s house to create “laser scan” images.
The fact that there were two cameras used to create the images, instead of relying on one, did not affect his conclusion that Read’s taillight could not have touched O’Keefe’s vehicle that morning when the two vehicles made contact.
In another set of questions, Brennan asked Welcher whether he ever used an encrypted messaging app, such as Signal, to communicate with the district attorney’s office.
“No, I don’t even know what that is,” Welcher said.
Brennan has criticized communications by the defense team with their own crash experts from the company ARCCA using Signal.
Alessi stepped up again for another round of cross-examination. He asked whether there were any slides in his PowerPoint presentation that explored alternative theories to Read’s SUV hitting O’Keefe.
“I mean, I had 130 slides. I suspect I bored some of these people to death already, so I didn’t include everything,” Welcher said. “There was a bunch of testing I did with the Lexus about backing and pedestrian detection that, you know, removed certain hypotheses. So if I was able to eliminate a hypothesis, I didn’t present it here.”
Alessi concluded his questioning of Welcher, and the witness stepped off the stand.
Brennan then played a video of a media interview with Read.
“I thought, ‘Could I have run him over?’ Did he try to get me as I was leaving and I didn’t know? I mean, the music was blasting, it’s snowing … Did he come and hit the back of my car and I hit him in the knee?” Read said, adding that after she hired her attorney, David Yannetti, she asked him the same questions.
“Then you have some element of culpability,” Read recounted Yannetti telling her.
The judge called the lawyers to a sidebar discussion and sent the jury out of the courtroom for a short recess.
The trial will proceed with the defense calling their witnesses. It’s unclear if they will begin on Thursday since the judge previously said it will be a half-day.
10:47 a.m. – Questions about SUV suspension, ‘techstream’ data
Alessi spent more than 10 minutes questioning Welcher about whether his company knew about the height of Read’s suspension on the morning of Jan. 29, 2022.
“You don’t have the suspension height for that key date, do you?” Alessi asked.
“Sir, I only have it two days later,” Welcher said.
Alessi then turned his questioning to techstream data from the Read SUV.
“The text stream information doesn’t tell you when a collision occurs, does it?” Alessi asked.
“Correct,” Welcher said.
Alessi concluded his cross-examination and the judge called for a morning break.
10:16 a.m. – Defense questions scans of Read and O’Keefe vehicles
After jurors entered the room, Welcher returned to the stand for his third day of testimony. Cross-examination began on Wednesday with defense attorney Alessi.
Questions began over pieces of glass found on the bumper found on Read’s SUV.
Welcher said he does not have enough evidence to conclude whether the glass on the bumper is from a broken glass found at the scene, which investigators say are from a glass taken from a bar by O’Keefe and Read.
“We have pictures of a broken bar glass in the snow near where Mr. O’Keefe’s body was. We have glass fragments on the rear of the bumper. That’s the extent of my knowledge on the correlation between those two,” Welcher said.
Alessi asked Welcher to assume that testing conclusively determined that the glass on the bumper is different from the glass in the snow, Welcher said it would not affect the end result of his analysis.
“I’d want to know where the glass came from, but we still have a whole bunch of other elements,” Welcher said.
Welcher said that the reports about the glass were “inconclusive,” and Alessi proded him on whether he read “all of the reports.”
“Apparently not,” Welcher said. A state police crime lab analyst testified last week that glass from the scene did not match glass found on Read’s bumper.
Alessi then turned questions to “laser scans” conducted by Welcher in a process known as photogrammetry, defined as using photography in surveying and mapping to measure distances between objects.
Aperture, the company Welcher works for, created digital images of O’Keefe’s driveway as part of their analysis of whether Read’s SUV could’ve been cracked when it backed up into O’Keefes Chevrolet the morning he died.
Welcher was questioned about two different cameras that were installed at O’Keefe’s house in Canton. The camera used by Welcher’s company in October 2024 differed from the one at the house on Jan. 29, 2022.
Welcher said his company “accounted” for the differences in angles between the two cameras as part of their analysis.
“You didn’t measure the distortion, sir, did you?” Alessi asked.
Analysts used the images from the old camera and from the new camera, Welcher said, and they worked within a margin of error in an “acceptable range, so that we have confidence in our results,” Welcher said.
Knowing the different models used for the Ring cameras used at O’Keefe’s home were not relevant, Welcher said.
Alessi pulled up a slide from Welcher’s presentation that shows Read’s Lexus and O’Keefe’s Chevrolet close to each other. The image was created using laser scans and shows angles not captured on O’Keefe’s Ring video.
Images of Karen Read’s Lexus and John O’Keefe’s Chevrolet shown during Read’s retrial on Thursday, May 29, 2025. The images were created with laser scans by Aperture, a company hired by the prosecution.Court TV
Alessi asked if the image showed contact with Read’s taillight, but Welcher said, “It absolutely is not.”
“It’s probably within an inch of making contact,” Welcher said.
Alessi showed another slide, which shows images of the two vehicles very close, but Welcher again said the image did not show contact between the taillight of Read’s SUV and O’Keefe’s car.
Welcher argued that the images were two dimensional and did not show the depth.
“You lose in two dimensional images, you lose one dimension depending on which way you’re looking,” Welcher said.
Alessi moved on from the topic.
9:33 a.m. – Hearing kicks off the day, judge weighs in on line of questioning from defense
Alessi began the day by arguing issues he has with the PowerPoint slides used by Welcher in his testimony. The morning’s hearing took place before jurors were called into the courtroom.
The judge eventually ruled that she will limit some of line of questioning that the defense can go into with Welcher.
Alessi sought to ask more questions about Welcher’s reliance on a state police reconstructionist’s reports and the state’s medical examiner who conducted O’Keefe’s autopsy.
Read’s lawyer took issue with an odometer reading of Read’s SUV that Welcher used as a “starting point” to determine the locations and times for the events on Jan. 29, 2022.
Welcher used Massachusetts State Police Trooper Joe Paul’s odometer reading as the “the foundation for Dr. Welcher’s entire analysis,” Alessi said. Paul is an accident reconstructionist with the state police.
There were parts of the slideshow that relied on photographs and images from Paul’s reconstruction analysis and the autopsy report by Dr. Irini Scordi-Bello.
Alessi said that the key cycles of Read’s SUV that Paul relied on were contested during the first trial and continue to be contested during this second trial.
He said that “serial objections” interrupted his cross-examination on Wednesday and that the witness and prosecution are “cherry picking” information and preventing a full cross-examination of Judson’s opinions on aspects of Paul’s and Scordi-Bello’s reports.
“Litany of complaints,” Brennan said in response to Alessi’s arguments.
Brennan said that Welcher did not rely on the analysis of Paul or the “undetermined” manner of death reached by Scordi-Bello.
“If they want to call Trooper Paul, well, maybe they can try to do that, but Dr. Welcher is not the right witness for it,” Brennan said. “You cannot vouch for the credibility of another witness.”
Judge Beverly Cannone denied Alessi’s attempts to question Welcher about Paul’s analysis and Scordi-Bello’s conclusions.
Read more: Recap of Tuesday’s testimony
Read, 45, is charged with second-degree murder in the death of O’Keefe, who was found outside the home of a fellow Boston police officer on Jan. 29, 2022.
Norfolk County prosecutors say Read struck O’Keefe with her SUV while driving intoxicated. Read’s attorneys say her car never struck O’Keefe and that others are to blame for his death.
