Karen Read retrial: Here’s how Wednesday unfolded

Crash specialist concludes testimony — 3:32 p.m.

By Travis Andersen, Globe Staff

After the sidebar, Andrew Rentschler told prosecutor Hank Brennan he didn’t know the size of the initial search area at the scene.

“I saw the area where [an officer] was blowing with the leaf blower,” Rentschler said.

Brennan asked if most of the injuries to John O’Keefe were on the right side of his body.

He said some injuries were but the “skull fracture is a little bit to the right, but it’s mainly on the back of his head.”

Brennan asked how Read’s taillight broke.

“I don’t know,” Rentschler said. “There’s no evidence of how it broke.”

He then stepped down, and the lawyers came back to a sidebar.

Judge Beverly Cannone sent jurors home shortly before 3:40 p.m. “We will see you tomorrow morning,” she said before they exited the courtroom.

Crash specialist testifies on redirect — 3:25 p.m.

By Travis Andersen, Globe Staff

After the sidebar, Andrew Rentschler told Read lawyer Alan Jackson that when he previously testified that “they” had provided him information about the case, he wasn’t referring to the defense team.

He said that was “a client,” meaning the federal government, which initially hired Rentschler’s firm, ARCCA.

Rentschler told Jackson he doesn’t know when or how the pieces of plastic ended up at the scene on Fairview Road.

He told Jackson he was aware that none of the plastic Brennan showed him was found at the time O’Keefe’s body was discovered in the snow. Prior witnesses have said debris was recovered in installments days after O’Keefe’s death as the snow started to melt.

Rentschler told Jackson that O’Keefe’s injuries “are not” consistent with being struck by Read’s Lexus.

Brennan asked on recross if O’Keefe could have been hit with “a clip.”

”I don’t believe that’s consistent with the evidence,” Rentschler said.

Brennan asked Rentschler when he thought the glass was removed from O’Keefe’s nose, and he said he believed it was the morning his body was found.

Brennan asked if Rentschler saw evidence that O’Keefe had been holding a drinking glass at the scene, and the lawyers returned to a sidebar.

‘I don’t think he even got hit by the car, sir,’ crash specialist testifies — 3:02 p.m.

By Travis Andersen, Globe Staff

Prosecutor Hank Brennan noted the test dummy’s feet were twisting upon impact in some of the ARCCA testing done for the government.

“Could it cause a person to stagger backwards?” Brennan asked.

“Is it possible?” Andrew Rentschler said. “I can’t say it’s impossible, but there’s no evidence of that.”

Brennan asked if a person struck could get their foot caught on a curb, lose a sneaker, then stumble backwards and fall on their head.

“I mean, I guess you could somehow predict or have a possibility of almost anything happening,” Rentschler said. “You could say someone could get hit by a car and do a couple somersaults into the yard.”

Brennan asked if he thought John O’Keefe “did somersaults” onto the Fairview lawn.

“I don’t think he even got hit by the car, sir,” Rentschler said.After a sidebar, Brennan put up a photo of the cut on O’Keefe’s nose.

He asked Rentschler if he considered that a piece of glass was pulled from O’Keefe’s nose.

“I was aware there was some piece of material allegedly pulled from the nose,” Rentschler said.

Read told an interviewer she pulled a piece of glass from O’Keefe’s nose when she discovered his body.

Rentschler told Brennan he believes a broken drinking glass was also found in the vicinity of O’Keefe’s body.

Rentschler told Brennan he’s also aware a drinking straw was located at the scene.

Brennan asked if he considered the glass evidence at the scene.

Rentschler said he “especially” looked at the glass in O’Keefe’s nose and considered whether that could result from a vehicle strike.

He told Brennan he doesn’t remember when he found out about the glass in O’Keefe’s nose; Brennan played the interview clip earlier in the trial.“It might have been in an interview or something,” Rentschler said.

Brennan presented a transcript of some of Rentschler’s prior testimony when he said “they” had informed him about “testimony and situations and events” that helped him understand what was happening at trial.

The lawyers came back to a sidebar after Brennan said he had no further questions.

Prosecutor asks crash specialist if he knew pieces of Read’s broken taillight were found on John O’Keefe’s clothes — 2:56 p.m.

By Travis Andersen, Globe Staff

After the sidebar, prosecutor Hank Brennan asked defense witness Andrew Rentschler if he knew plastic pieces were removed from John O’Keefe’s clothes.

“I was aware that samples were recovered, yes,” Rentschler said.

He said he knew those pieces were consistent with Read’s broken taillight.

Rentschler said that without a biomechanical analysis, “you can’t determine exactly how or if” those pieces “were deposited there as the result of” a collision.

Rentschler said “first you have to know how the incident occurred.”

“Without knowing how this happened, you can’t just then look at other evidence and try to predict how it happens,” he said. “You need the actual evidence to look at the event. This all goes to the event. You need contact with the arm, I guess apparently, to actually cause this.”

Brennan noted some of the recovered plastic had “fibers” in it when placed under a microscope.

“If you can’t even tell that an impact occurred, you can’t just look at tertiary evidence and say ‘well this proves that it occurred,’” Rentschler said.

He said the recovered shards under a microscope “look sharp.”

Brennan asked if any of the shards could cause an abrasion.

“I don’t think that you could get a consistent level of superficial abrasions along the entire arm of minimal depth of less than half a millimeter through impact with the glass,” Rentschler said. “To have that minimal force on every part of the arm to only cause superficial abrasions would be highly unlikely.”

He told Brennan that his firm did not put a drinking glass in the dummy’s hand during the testing, nor did they count the taillight pieces that shattered.

He also told Brennan the break could “look different” in the tests depending on the positioning of the arm.

Rentschler said the taillight debris had “some spread” in the testing upon impact.

Crash specialist continues testimony — 2:43 p.m.

By Travis Andersen, Globe Staff

After the sidebar, Andrew Rentschler told prosecutor Hank Brennan that government witness Judson Welcher “did not state” in his report that his paint crash test was a reenactment of the details of the actual collision.

“There was one test with the arm like this,” Renstchler said. “I have not seen any other explanation of what happened or how it occurred.”

Brennan again asked if Welcher ever said he was “trying to represent the exact posture, movement, and stance” of John O’Keefe in the paint test.

“It’s not stated,” Rentschler said, adding that he would be “curious” to find out what the intent of the test was if not that.

Brennan asked if he had ever seen cases where variables are “impossible to predict.”

Rentschler said “there could be, yes. … I suppose I probably have.”

He told Brennan he’s done “hundreds” of pedestrian crash cases. He said he was not present for ARCCA’s crash tests.

If a dummy was restrained by a forklift, Brennan said, “it does not allow the crash test dummy to be thrown, does it?”

”Assuming there is a throw, that’s correct,” Rentschler said.

Brennan asked if the dummy would be dragged like a real person, and Rentschler said “if there’s any drag pushing it forward, it’s going to sway that way.”

Brennan asked why Rentschler removed a section of an article included in his PowerPoint that stated frontal collisions can be at angle, deflecting the pedestrian to “one side.”

Rentschler said he did not include that passage because O’Keefe was allegedly hit while the car was in reverse.

Brennan asked if he knew the position of O’Keefe’s arm at impact, and Rentschler said, “I don’t know the position of the arm at impact, because it wasn’t hit” by a vehicle.

He told Brennan he did not consider phone data as part of his analysis. He also said he didn’t consider phone and battery temperature figures, which he said have “nothing to do with biomechanics, sir.”

Rentschler told Brennan there were debris fields in some of the test collisions that his firm, ARCCA, ran.

“You don’t need to look at debris fields, or the alleged debris field,” Renstchler said. “That has nothing to do with the injuries or the position or the movement.”

Brennan put up photos of taillight shards discovered on the lawn of the Canton home.

“I was aware there was debris in the yard, but again, that has nothing to do with the biomechanical analysis,” Rentschler said.

He said there are “certainly different possibilities” for how the debris ended up on the lawn.

Brennan put up a photo of O’Keefe’s hat discovered at the scene.

“There’s a number of ways a hat can end up in a yard,” Rentschler said.

“Do you have a theory you want to share with us about planting evidence?” Brennan asked.

Judge Beverly Cannone sustained a defense objection.

Rentschler said he also didn’t consider how O’Keefe’s shoe ended up near the curb.

He told Brennan he believes “there was evidence collected like that” when the prosecutor asked if he knew taillight shards were recovered from O’Keefe’s clothing.

The lawyers came back to a sidebar.

Crash reconstruction specialist continues testimony under cross — 2:17 p.m.

By Travis Andersen, Globe Staff

Andrew Rentschler told prosecutor Hank Brennan that he evaluated Judson Welcher’s opinions “and the one test he ran.” Welcher testified for the prosecution as an expert witness and determined John O’Keefe’s injuries were consistent with being hit by a car.

Brennan asked if Welcher said anywhere in his report that the arm angle in his demonstration was meant to show exactly how O’Keefe’s arm was positioned upon impact.

“I guess there is no opinion or conclusion that he knows how Mr. O’Keefe was actually positioned at the time of this alleged incident,” Rentschler said. “He does not state what he thinks the speed is.

”He said Welcher also doesn’t state how far he thinks O’Keefe was thrown on impact.

Brennan asked if a crash test can’t replicate the actual circumstances of a collision, “you would agree that would not be a reliable test to present to a jury, don’t you?”

Judge Beverly Cannone called the lawyers to a sidebar.

Crash reconstruction specialist continues testimony — 2:12 p.m.

By Travis Andersen, Globe Staff

Prosector Hank Brennan continued his cross-examination of Andrew Rentschler after the lunch break.

He told Brennan no MRIs were taken of John O’Keefe’s arm injuries. He said a crash test dummy responds like a human being “to a certain extent,” but there are “certainly” differences.

“That’s why you have to look at the acceleration and the force,” Rentschler said.

Brennan asked how many references to scholarly articles were contained in his May 7 report.

“Twenty-six, I think,” Rentschler said. “They support the opinions, or the methodology, or both.”

Brennan asked if Rentschler’s references ever suggested it was appropriate to use a crash test dummy to determine whether there would be “documented damage to someone’s skin” from a collision.

“No it didn’t, and that’s not what I did” in the Read case, Rentschler said.

Brennan said one study listed a number of other materials that should be used, and Rentschler said that study was for “laminated glass” and its “cut-ability.”

Brennan cited additional studies that don’t say a crash test dummy is appropriate for the testing.

He asked Renstchler if prosecution witness Judson Welcher ever claimed his testing was meant to represent exactly how O’Keefe’s arm was positioned upon impact.

Rentschler said if Welcher “didn’t intend to do that, then there’s no evidence that he can provide with respect to the arm impact at all.”

He said “it would be pretty odd if the one test he ran didn’t actually represent what he thought happened.”

Images of a video ARCCA produced simulating an arm being struck at 29mph resulting in a broken tail light during the Karen Read retrial in Norfolk Superior Court, Wednesday, June 11, 2025, in Dedham, Mass. Greg Derr/Associated Press

Crash reconstructionist continues testimony under cross-examination — 12:42 p.m.

By Travis Andersen, Globe Staff

Prosecutor Hank Brennan asked if Andrew Rentschler had “free rein” to do whatever testing he wanted when he was first hired, and Rentschler said there were some constraints around the budget, when his firm, ARCCA, was initially hired by the federal government.

He did not specify the federal government, as jurors are barred from learning that the Justice Department initially hired ARCCA to review the case as part of a federal investigation into state law enforcement’s handling of John O’Keefe’s death.

The defense later retained ARCCA separately. No one was charged with any federal crimes in connection with the case.

Rentschler told Brennan “depends what it is” when he asked if he writes things down to remember them.

Rentschler told Brennan he hasn’t had any peer-reviewed articles since 2003. Brennan read off the titles of those papers, which dealt mainly with wheelchair technology.

“Do any of them deal with pedestrian collisions?” Brennan asked.

Special prosecutor Hank Brennan questions ARCCA accident reconstruction expert Andrew Rentschler on the witness stand during the Karen Read retrial in Norfolk Superior Court, Wednesday, June 11, 2025, in Dedham, Mass. Greg Derr/Associated Press

“No they don’t,” Rentschler said, adding that a book chapter he has written also doesn’t deal with pedestrian crashes.

Brennan asked if Rentschler listed pedestrian collisions as one of his specialties on his resume.

“Not specifically, that actually falls under impact biomechanics,” Rentschler said.

He told Brennan that when he ran the 29 m.p.h. test, there were 863 G’s of pressure transferred onto the crash dummy hand.

Brennan asked if any of O’Keefe’s arm wounds looked like punctures.

“I don’t make medical diagnoses,” Rentschler said. “That was what was diagnosed by the medical records.”

He said the medical records indicated O’Keefe suffered no fractures.

Rentschler told Brennan he didn’t believe any MRIs were taken; normally X-rays don’t capture certain injuries, including soft tissue damage, Rentschler said.

Brennan asked if a person can be struck by a vehicle and come away with no injuries, and Rentschler said it depends on a variety of factors, including speed.

He told Brennan the absence of a bruise in and of itself doesn’t rule out a collision.

“You have to look at all the evidence,” Rentschler said.

“And you have to look at the force. If there’s 4,000 pounds of force applied to the body or to the arm, then certainly you would expect a bruise. And if there’s no bruise, then you would have to question if that impact or contact actually occurred.”

Brennan asked if plastic can “shatter differently,” and Rentschler said “I doubt that it shatters exactly the same way” on impacts.

Brennan asked if he’s ever seen plastic break “differently,” and Rentschler said the taillight plastic broke differently when ARCCA ran the collision tests.

He told Brennan the size of the debris differed, as did the angles of the breaks on each simulation.

Rentschler said he did not count the broken pieces of debris after each collision.

Judge Beverly Cannone called the lawyers back to a sidebar after the defense repeatedly objected to the tone and commentary that Brennan used while questioning the expert.

Jurors exited the courtroom for their lunch break around 12:45 p.m., while the attorneys remained at a sidebar.

Crash reconstructionist continues testimony under cross-examination — 12:20 p.m.

By Travis Andersen, Globe Staff

After the sidebar, defense witness Andrew Rentschler told prosecutor Hank Brennan his employer “told us about certain evidence” before he testified last year, but he did not contact anyone involved in the first trial.

Rentschler said the information made no difference to his analysis or conclusions.

“It doesn’t change the facts that I evaluated,” he said.

“It hasn’t changed anything I’ve ever testified to.”

Brennan asked if he was “denying” that receiving information helped him prepare.

“It didn’t change my opinion,” Rentschler said, adding that he was told about “trace DNA” found on the vehicle.

He said he understood “what the theory was,” so saying “there’s trace DNA doesn’t change anything.”

Rentschler said he spoke with the defense a couple of times by phone before he testified in the first trial.

Brennan asked if they discussed how Rentschler could “portray” himself as independent before the first jury.

“There was no need to, because it was independent,” Rentschler said, adding that the defense provided him a ride to and from the airport.

Brennan asked if he had told the defense that he preferred to take an Uber to appear independent.

Rentschler said he didn’t take an Uber and “it didn’t even cross my mind.”

He said he had a “ham sandwich” with the defense after his testimony the first time, and a camera crew was present.

Brennan asked if Rentschler was discussing the case and “laughing it up a little bit” with the defense.

“Whatever was spoken about at the table, I’m sure I heard,” Rentschler said.

Brennan asked if Rentschler recalled “accolades” he received during that conversation, and he said he did not remember what was said.

Rentschler said he might have spent about 10 minutes with the defense eating his sandwich before he got a ride back to the airport.

He said his firm, ARCCA, billed the defense for time and travel after the first trial.

“I have no idea if they paid it or not,” Rentschler said.

He said he doesn’t know how much ARCCA has been paid for its work on the case.

Brennan asked if Rentschler deleted texts he had with defense, and he said he’s sure he deleted the texts, which were mainly about scheduling. He said he did not communicate with the defense with Signal, a messaging app.

Daniel Wolfe, Rentschler’s colleague at ARCCA, did communicate with Jackson via Signal, per prior records and testimony.

Rentschler said he and Wolfe worked on the case with another analyst named Scott Klein.

Expert witness for defense testifies under cross-examination — 12:04 p.m.

By Travis Andersen, Globe Staff

Following the morning break, Andrew Rentschler told prosecutor Hank Brennan that facts and details matter in analysis.

Rentschler told Brennan he indicated O’Keefe’s body was found 10 to 20 feet from the road.

“You have no idea where the point of impact was in this collision,” Brennan said.

“Nobody does,” Rentschler said. “There’s no evidence.”

Brennan put up a crime scene photo that appeared to show O’Keefe’s body close to the roadway.

“Twenty feet, Dr. Rentschler?” Brennan asked.

“The way I explained it to you, yes sir, 10 to 20 feet,” Rentschler said.

He told Brennan the dummy used in his firm’s testing was about 5-foot-9 and weighed a little more than 170 pounds, compared to O’Keefe who stood 6-foot-1 and weighed 216 pounds.

Brennan said the lighter weight “changes the force equation,” and Rentschler said, “that can, yes.”

Brennan asked if Rentschler was getting updates from his employer on the case before he testified at the first trial last year.

The lawyers then came to a sidebar.

Crash reconstructionist continues testimony — 11:19 a.m.

By Travis Andersen, Globe Staff

Following the sidebar, Andrew Rentschler said it’s not accurate to say the head is the most commonly injured bodily region in pedestrian strikes, as stated by an article published in 1979 that Aperture cited.

He said Aperture, the firm that conducted crash testing for prosecutors, dropped a dummy’s head on a concrete surface.

In a video of the test, the dummy “falls rigidly backwards, almost like a tree, and impacts the concrete,” Rentschler said.

Read lawyer Alan Jackson played the video clip of that dummy falling backward in the Aperture testing.

“Obviously there’s no musculature” on the mannequin, Rentschler said, adding that the dummy did not slide backwards on impact. “It just dropped and … hit directly on the floor.”

After a sidebar, Rentschler said he believes the evidence is “inconsistent” with O’Keefe being hit by the SUV on his right arm and then “moving laterally into the yard and falling backward onto the back of his head.”

Judge Beverly Cannone called a morning recess around 11:25 a.m.

Prosecutor Hank Brennan will cross-examine Rentschler when testimony resumes.

Defense witness Andrew Rentschler of ARCCA on the stand during the Karen Read retrial in Norfolk Superior Court, Wednesday, June 11, 2025, in Dedham, Mass. Greg Derr

‘There wasn’t even an indication on the arm of where it would have contacted the vehicle,’ crash reconstructionist testifies — 11:05 a.m.

By Travis Andersen, Globe Staff

Andrew Rentschler said he would expect John O’Keefe’s right hand to be fractured on impact, but “there were no indications whatsoever of that.

”The same holds true for the elbow, he said.

“There was no trauma, there were no fractures, there wasn’t even an indication on the arm of where it would have contacted the vehicle,” Rentschler said. “There was no bruising, there were no lacerations, there was nothing at the alleged point of contact which would indicate an impact that produces thousands of pounds of force on the arm.”

He said there was no indication O’Keefe was struck at his center of mass; authorities have said the collision was more of a sideswipe impact.

Rentschler said he doesn’t believe a glancing blow could have propelled O’Keefe to the area of the yard where he was found.

“I don’t believe it’s possible,” he said. “I’ve seen no research that would indicate that would occur.”

He said the lower extremities are the most commonly injured regions of the body in pedestrian strikes.

O’Keefe’s only injury in that part of his frame was a half-centimeter abrasion on the outside of his right knee, he said.

“I do not believe that injury is consistent with being struck by an SUV at 24 m.p.h.,” Rentschler said.

Rentschler also cited a medical study in which cadavers were struck by vehicles at 24 m.p.h.

“There’s extensive damage to the legs of all three of the cadaver subjects that were struck at 24 m.p.h.,” he said, adding that the corpses in that study came from people who had donated their bodies to scientific research.

He said the prosecution experts found that the totality of evidence was consistent with Read’s SUV striking O’Keefe, and O’Keefe hitting the back of his head on the ground.

The lawyers came back to a sidebar.

Karen Read stands in the middle of her attorneys at sidebar with special prosecutor Hank Brennan and Judge Cannone during her retrial in Norfolk Superior Court, Wednesday, June 11, 2025, in Dedham, Mass. Greg Derr/Associated Press

Crash reconstructionist continues his testimony — 10:53 a.m.

By Travis Andersen, Globe Staff

Andrew Rentschler said his firm, ARCCA, had a taillight strike a dummy arm at 15 miles per hour in reverse.

“There was not enough force … to actually fracture the taillight” at that speed, he said.

Another lab test repeated the simulation at 17 m.p.h, he said, generating “more than enough” force to break a bone or tear ligaments.

He said ARCCA also had a dummy arm struck by a replica SUV at 24 m.p.h. in reverse.

Rentschler said the dummy’s feet were “barely touching” the ground in the testing.

Defense attorney Alan Jackson questions witness Andrew Rentschler of ARCCA an accident reconstruction firm during the Karen Read retrial in Norfolk Superior Court, Wednesday, June 11, 2025, in Dedham, Mass. (Greg Derr/The Patriot Ledger via AP, Pool)Greg Derr/Associated Press

Jackson played video clips of that impact at 24 m.p.h.

“The arm’s accelerated up and pushed away from the body” on impact, Rentschler said. “It’s putting a lot of force and pressure on that appendage.”

He said if John O’Keefe was holding a drinking glass at the time of impact, the taillight would first strike his exposed knuckles and then “likely hit along the forearm” and near the elbow.

Rentschler said he saw no evidence of any dislocations or fractures to O’Keefe’s arm.

He said taillight material was broken during the 24 m.p.h. test, with the debris moving forward with the vehicle as the “arm has been pushed away.”

Rentschler said O’Keefe was found 10 to 20 feet from the road in the front yard.

“He can’t get to where he ends up before the taillight fragments have already gone forward and been deposited on the ground,” Rentschler said.

He said the dummy’s right sleeve showed “no defects at all” following the 24 m.p.h. test.

Prosecutors say Read’s SUV was moving at that speed when she struck O’Keefe.

Rentschler said ARCCA also had a replica SUV back into a suspended dummy arm at 29 m.p.h.

“There is extensive damage” to the lift gate at that speed, he said.

Rentschler said ARCCA also had the SUV back into a dummy straight on at 29 m.p.h.

He said at that speed on a center mass, you’d expect to see the taillight debris go straight back, and the body would move in that direction as well.

He said O’Keefe’s wounds were “not consistent with contacting and fracturing the taillight cover,” based on the abrasions and sweatshirt tears.

“At these speeds, you would likely expect fractures,” Rentschler said.

Defense expert faults method, conclusion of prosecution expert — 10:30 a.m.

By Travis Andersen, Globe Staff

Andrew Rentschler said he did not see “a single peer-reviewed article” in Aperture’s report vouching for the paint transfer test. Two specialists who worked for Aperture testified earlier in the trial that John O’Keefe’s injuries were consistent with being hit by the taillight of Karen Read’s SUV.

He said you would expect to see “horizontal” abrasions on O’Keefe’s forearm if the taillight struck it at a 90-degree angle as Aperture stipulated in its report.

“They’re not,” he said of the forearm abrasions. “You can see some of them are vertical, some of them are angled, some of them it’s hard to tell what the directionality is.”

Rentschler said “you would not” see the injury patterns on O’Keefe’s arm if it was struck in the manner posited by the government experts.

He said the subject in the Aperture testing “pushes his elbow forward, leans into the car against the light, and then rolls off.”

Rentschler said the paint transfer test can only show the “approximate area of where the arm was covered in paint as the surrogate” places his elbow against the taillight cover.

He said O’Keefe’s injuries “don’t correspond to how the arm would interact with the vehicle if it was at a right angle and struck by the rear of that vehicle.”

He said the Aperture testing “only puts paint on the arm” but doesn’t show how the taillight cover would shatter and impact the arm, “if that’s even possible.”

Defense witness says John O’Keefe’s injuries ‘inconsistent’ with being struck by Read’s taillight — 10:16 a.m.

By Travis Andersen, Globe Staff

Following the sidebar, Andrew Rentschler identified more photos of John O’Keefe’s clothing.

He also identified another autopsy photo of O’Keefe’s right arm.

Rentschler said O’Keefe had 36 superficial abrasions on his right arm,“conservatively.“

”You need 36 different points of contact” to pierce the sweatshirt and contact the skin, Rentschler said, adding that the right sleeve had “nine defects.”

He said the prosecution’s analysts concluded that the area of the taillight “corresponds to the area of the upper arm.”

But Rentschler said O’Keefe’s injuries are “inconsistent” with getting struck by the taillight.

He said if the taillight were responsible for the abrasions, “you’d have to correlate them and line them up with contact, 36 different contacts from the taillight.”

He said Aperture took “no measurements at all” to determine where the blue paint “extended” on the subject’s arm in the test.

“You can’t say with any scientific certainty that that area of paint corresponds to where the abrasions are,” Rentschler said.

Crash reconstructionist describes his review of John O’Keefe’s injuries — 9:50 a.m.

By Travis Andersen, Globe Staff

Andrew Rentschler said he also reviewed John O’Keefe’s medical records.

“They are the sources you go to to determine what the injuries are,” he said.

He told Read lawyer Alan Jackson that there “were no [diagnoses] or references to fractures on any part of his right arm or hand.”

Rentschler identified an X-ray photo of O’Keefe’s right hand on the monitor.

“If X-rays exist, you need to review them,” he said.

He told Jackson he detected no injuries to O’Keefe’s right hand in the X-ray.

“You could actually see the fracture lines on the bones” if his hand were fractured, Rentschler said.

Rentschler said he also saw no defects or trauma in an X-ray photo of O’Keefe’s right forearm.

“I did not note any indication or any signs of trauma or injuries at all,” Rentschler said, adding that the same held true for the upper arm. “There’s no indication of any type of acute injury … to Mr. O’Keefe’s right arm.”

Rentschler said he also looked at photos of O’Keefe’s hooded sweatshirt.

“There were nine different punctures or holes” on the right sleeve, Rentschler said.

The lawyers came back to a sidebar.

Crash reconstructionist testifies on direct examination — 9:42 a.m.

By Travis Andersen, Globe Staff

Andrew Rentschler said it would “not be proper” for an analyst to ignore a victim’s clothing in a vehicle strike while conducting a review.

He said Aperture’s “paint transfer test” involved a person similar in size to John O’Keefe standing behind a test SUV, which had blue paint on the taillight area.

Aperture concluded that the cuts on O’Keefe’s arm were “consistent with the geometry and orientation of the right taillight” of Read’s SUV, based on the blue paint that ended up on the subject’s arm, he said.

“It has nothing to do with force,” Rentschler said of the test. “It doesn’t describe the force exerted on the taillight or on the arm. It doesn’t describe how the arm would have moved.”

He said Aperture described the wounds on O’Keefe’s arm as lacerations, but “they’ve been diagnosed as superficial abrasions.”

He said abrasions “take much less force, they’re less severe” than lacerations.

Crash reconstructionist resumes testimony — 9:36 a.m.

By Travis Andersen, Globe Staff

Following the sidebar, Andrew Rentschler told Read lawyer Alan Jackson that his firm, ARCCA, did testing based on the review of the Aperture analysts’ work.

Rentschler said a biomechanical analysis requires a number of tests including lab and field testing.

“It’s all based on the scientific method,” Rentschler said.

He said one question was whether the cuts to John O’Keefe’s right arm were caused by the taillight of Read’s SUV.

“You have to develop tests to get data to actually back up your hypothesis,” Rentschler said.

“If your results don’t match up with your hypothesis, you have to reevaluate. … That’s what experts do.“

Judge Beverly J. Cannone repeatedly sustained government objections when Rentschler discussed his children and when he spoke at length about various aspects of his work.

Cannone told Jackson he must stick to a more narrow “question and answer” format with the witness.

Rentschler said the Aperture blue paint testing, described earlier in the trial, had a person’s arm at 90 degrees from the rear of the SUV, with the subject wearing the same clothes O’Keefe had on at the time of the alleged collision.

“Clothing … can tell you how the impact occurred,” Rentschler said.

Crash reconstructionist resumes testimony — 9:21 a.m.

By Travis Andersen, Globe Staff

Andrew Rentschler hopped back on the stand around 9:15 a.m.

He told Read attorney Alan Jackson that he prepared a PowerPoint presentation laying out his findings.

Rentschler said he wanted to “evaluate the evidence” in the matter.

He said he looked at the testing work of Aperture, a forensic company the government hired.

The lawyers came to a sidebar.

Testimony resumes Wednesday — 8:50 a.m.

By Travis Andersen, Globe Staff

Testimony in Karen Read’s murder retrial resumes Wednesday in Norfolk Superior Court.

On Tuesday, Judge Beverly J. Cannone said the jury could get the case by Friday, or Monday at the latest.

Read, 45, has pleaded not guilty to charges including second-degree murder for allegedly backing her Lexus SUV in a drunken rage into her boyfriend, Boston police officer John O’Keefe, early on Jan. 29, 2022, after dropping him off outside a Canton home following a night of bar-hopping.

Her lawyers say she was framed and that O’Keefe entered the property, owned at the time by a fellow Boston police officer, where he was fatally beaten and possibly mauled by a German Shepherd before his body was planted on the front lawn.

Read’s first trial ended in a hung jury and she remains free on bail.

Jurors will finish hearing testimony Wednesday from defense expert Andrew Rentschler, a crash reconstructionist who determined the injuries to O’Keefe weren’t consistent with a vehicle strike, a finding at odds with a government expert’s opinion.