Behind the Wheel: What the Lexus Reveals

🗓️ Analyzing the Timeline: The Lexus Data

The Lexus vehicle’s “running clock” starts when the engine is turned on, likely around 12:12 a.m. The key incident (impact) occurred 19 minutes later, at 12:31–12:32 a.m., which matched the iPhone GPS timestamp and other data points.

Key findings:

• First event (three-point turn): Occurred at 12:24 a.m.
• Second event (incident): Detected at 12:31:57–12:32:02
• Vehicle logs matched real-time texting and movement

🚗 Reverse Maneuver: Vehicle Speed & Steering

The Lexus’s performance during this reverse maneuver told a vivid story. The RPMs shot up to 3300, the throttle was pressed to 74%, and the speed ranged from 13.6 to 23 mph. The vehicle backed up about 53 feet—and crucially, it swerved right with a leftward steer.

This leftward steering input, confirmed by the data, effectively dismantled the defense’s suggestion that the Lexus was being loaded onto a tow truck in Dighton during this trigger event, not operated by Karen Read.

📊TechStream Revelations: Key to Understanding Impact

Data extracted using TechStream revealed that reverse gear was engaged, brake activity showed distinctive on/off patterns, and the left steering input aligned with the direction of the swerve. One compelling clue was an RPM spike that wasn’t matched by a rise in speed—indicating the wheels may have been spinning, not accelerating. This cluster of findings pinpointed the time and mechanics of the impact with impressive precision, lending weight to the theory that John O’Keefe was struck during this maneuver.

🎨 Reconstructing the Scene: Laser Scanning, 3D Models and Exemplar Car

🤔 Karen Read’s Taillight Was Not Damaged When She Bumped John’s Traverse.

The engineer didn’t stop at data. He recreated the scene at John’s home, 1 Meadows Ave., using laser scanning equipment to determine whether Karen’s Read’s Lexus could have been damaged at 5:00am in the morning rather than the time she dropped off John.

Welcher presented video showing the exemplar Lexus bumping John’s car in the driveway and examined snow displacement to determine contact points. Notably, there were no shattered tail light fragments in the snow and only minimal scuff marks on the Lexus. From this, he concluded with a high degree of engineering certainty that the tail light was not damaged during that driveway bump.

🧠 Biomechanical Test: Simulating the Impact

To simulate how the injuries may have occurred, Welcher wore similar clothes to what John O’Keefe wore that fateful night and stood in for a biomechanical test using grease paint to model contact points. Welcher is appoximately the same height and build as O’Keefe.

Driving the exemplar Lexus at 2 mph, they studied how paint transferred onto the arm, and areas of impact from the vehicle to the head, and leg areas. The arm transfer aligned closely with John’s actual injuries, supporting the theory that the tail light clipped his arm.

Still, the expert carefully noted that they weren’t claiming to know exactly how O’Keefe was struck. Due to poor documentation at the scene, they were unable to calculate the trajectory or impact speed.

🎓 Forensic Limitations: What We Don’t Know

The lack of certain measurements meant:

• No known impact speed or throw distance
• No calculation for vehicle momentum or exact position
• Cannot use traditional formulas without proper data
• They defaulted to a “clipping” theory—a glancing blow, not a direct hit—consistent with Karen Read’s account and injury patterns.

🔮 Key Scene Evidence: Shoes, Hat, and Liquid

Photos and diagrams placed significant items with telling precision. John’s shoe was found near the curb, suggesting a likely impact point. His hat, discovered later on February 3, had no clear documented location beforehand. And…of course, we all know about the tail-light pieces and the broken glass. 

The Cross – Spoiler Alert: Welcher Still Knows More Than Alessi

Defense attorney Robert Alessi attempted to undercut Welcher’s credibility by suggesting his analysis wasn’t peer-reviewed. Welcher clarified that while his specific conclusions for this case haven’t been peer-reviewed, the methodology he applied is based on peer-reviewed science. The defense tried to exploit that distinction, but it didn’t land with much force. Welcher explained that work product in preparation for a trial typically isn’t peer-reviewed.

Alessi pressed hard on potential bias, invoking terms like confirmation bias and cognitive bias—similar to the tactic used against earlier witness Shannon Burgess. Welcher responded that he followed the scientific method and that bias plays no role in his conclusions. He acknowledged he’s not a cognitive or human factors expert, therefore, he couldn’t speak to those areas specifically.

The defense challenged Welcher’s sequence of questions during the reconstruction process, zeroing in on when he asked, “How did this happen?” Alessi suggested it should have come earlier in the scientific method, implying flawed logic. Welcher disagreed, emphasizing that gathering data comes first and hypotheses are refined continuously.

Alessi then floated the idea that the most likely hypothesis is the one that best explains the injuries. Welcher said it’s not that simple—it depends on the case and must be rooted in science and evidence, not just assumptions.

Shifting gears, Alessi brought up trooper reports and Aperture’s billing. The total expected bill is $400,000, but that covered work from multiple offices, and the CW will receive a credit when the exemplar Lexus is sold. Welcher kept his cool even as Alessi tried to imply undue influence. He confirmed he once said, “I don’t have a dog in the fight,” and stood by that.

A significant chunk of cross focused on Welcher’s presentation updates. Alessi aggressively questioned the timing of revisions made during the trial. Welcher explained that the original presentation was submitted on January 30, with an amendment on May 13 due to defense objections. He also removed material based on the judge’s orders just before his testimony. Alessi insisted this was suspicious, but Welcher said the changes were minor and meant to ensure accuracy.

Defense Witnesses from ARCCA will no doubt receive the same “updated reports” grilling that CW witnesses have enjoyed by Alessi, as ARCCA presented their update mid=trial as well, on May 8th.

Alessi grilled Welcher over a specific video clip. Welcher said he hadn’t seen it until April and added an alternative route based on it when he thought it was a new interview. The defense attorney grew increasingly frustrated, yelling about mid-trial changes. Welcher remained composed and said the alterations weren’t substantial.

More back-and-forth followed about a May 8 report from Shannon Burgess that changed the injury timeline. Alessi questioned whether Aperture had ever amended a report mid-trial. Welcher responded that while amended analyses had been done, he couldn’t speak for the entire company’s practices.

The key cycle data became another battleground. Welcher explained that text stream events are linked to specific key cycles and trips, making it virtually impossible to misassociate them. He emphasized that key cycle 1162 was accurate and supported by iPhone location data. Alessi tried to create doubt by mentioning other key cycles, but Welcher stayed firm on the integrity of the data.

Alessi questioned whether Welcher relied on Trooper Paul’s report. Welcher said no—he conducted his own work to avoid confirmation bias. Still, he had read Paul’s report. That prompted a sidebar with the judge.

Alessi attempted a deep dive into physics and injuries—asking about force formulas, bone fracture thresholds, and outdated statistics. Welcher educated the court on how modern safety features like airbags have shifted injury patterns. He maintained that most pedestrian-vehicle collisions today result in lower extremity injuries, not necessarily head trauma, and cautioned against drawing conclusions from decades-old data.

There was a long physics-based segment, including a video simulation that demonstrated how a fall onto a hard surface could cause a skull fracture. Welcher held his ground on Newton’s laws and formulaic calculations. At one point, he cited force levels in G’s, which likely flew over the jury’s head but impressed on technical grounds.

The injury above John O’Keefe’s eye was discussed—Welcher believes it may have been caused by the car’s spoiler, possibly the same impact that resulted in his fatal injury. He admitted he didn’t go inside the garage or access the entire scene but said he stayed off private property to avoid trespassing. His scanning equipment, however, captured the area with high precision from a distance.

A four-inch berm became a sticking point. Alessi argued that if O’Keefe had been standing on it rather than in the road, Welcher’s measurements would be inaccurate. Welcher tried to brush it off, but eventually conceded that the berm wasn’t factored into his diagram, and that could affect the accuracy.

When asked about force analysis, Welcher said he didn’t perform a full force calculation—just measurements. This surprised Alessi, especially since Welcher had described the impact as a “glancing blow.” The defense attorney seemed to sense an opening here but didn’t manage to fully exploit it.

After the lunch break, Alessi picked up with questions about driving in reverse at 24 mph. Welcher confirmed he had done so with a Lexus, presumably during testing. Alessi tried to be sarcastic when Welcher suggested something was technically possible, prompting an eye-roll moment as Welcher quipped about shooting into space.

The tone grew tense, but Welcher mostly stayed calm despite Alessi’s aggressive, sometimes theatrical style. A brief redirect followed, and the court moved to re-cross, which the judge instructed should be short. And that’s where the cross wrapped for the day—with Karen Read visibly agitated, jumping out of her seat to order additional questions during parts of the demonstration.

The response from Dr. Judson Welcher when Judge Cannone told him he was all set was priceless: “Oh my God!”, he exclaimed. 

Despite some fumbling through his presentation, the expert insisted his conclusions were rooted strictly in data—not in public opinion, legal narratives, or social media spin. He appeared uneasy when discussing data shared by Shanon Burgess but maintained that the data, not the drama, led the analysis.

The Aperture expert’s presentation was packed with technical depth, methodical evidence, and solid science. He provided robust support for the theory that John O’Keefe was struck during a low-speed reverse maneuver, that the tail light damage occurred at that moment—not later—and that this was a clipping impact, not a violent strike or the result of an indoor altercation.

In the end, it was a clear case of data versus drama—and this time, the data won.

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