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🔬 Expert Witness · Aperture LLC

Judson Welcher

Courtroom still of Judson Welcher.

Accident reconstructionist and biomechanical engineer with Aperture LLC

Trial 2
1,382 lines 9 proceedings

About

Judson Welcher testified for the Commonwealth about vehicle data, tail-light damage, and John O'Keefe's injuries. He interpreted a Toyota TechStream event from Karen Read's Lexus as showing forward motion followed by rapid reverse acceleration, but acknowledged that the data did not itself establish whether or when a collision occurred. Applying a revised clock comparison by his colleague Shanon Burgess, Welcher agreed that part of the event's possible time range fell after a lock event on O'Keefe's phone. Welcher testified that the location and orientation of O'Keefe's right-arm lacerations were consistent with the tail-light geometry of a physically identical Lexus. He said a glancing impact could produce serious upper-body injuries without leg fractures, and that a fall onto a hard surface could account for the skull fracture. His analysis of video from O'Keefe's residence addressed a different, low-speed contact between the Lexus and O'Keefe's Traverse; he concluded that the contact he measured could not have broken the upper right tail light. Judge Cannone allowed Welcher's collision and injury-consistency opinions but barred his conclusion that Read's specific Lexus struck O'Keefe. On cross-examination, defense attorney Robert Alessi challenged Welcher's lack of a case-specific force calculation for the arm injuries, his use of a replacement Ring camera in the video analysis, and his assumption about the Lexus's suspension height on the night in question. Welcher said his force analysis depended on how a load was distributed, defended the video work using scene scans and overlays, and acknowledged that he had not measured the earlier suspension setting. Alessi also questioned changes to Welcher's presentation and whether his work had tested a no-contact alternative. Welcher said he had tested and eliminated hypotheses, though no slide or document presented to the jury expressly showed that alternative.

Trial Record (9)

Trial 2 Retrial Apr 22, 2025 – Jun 18, 2025 9 proceedings

Day 21

Voir Dire Judson Welcher - Voir Dire Judson Welcher Robert Alessi 3 highlights 47 lines spoken
Summary

Defense attorney Alessi questions prosecution expert Judson Welcher about last-minute changes to his PowerPoint presentation and their impact on the collision timeline.

Highlights (3)
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“Mr. Brennan.”

Welcher identifies Brennan as the person who suggested unspecified presentation changes. He gave deletion of a slide referencing testimony he was not allowed to include as an example.

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“I wouldn't say it's insignificant. Again, I haven't modified my PowerPoint at all. I was happy with the data I had and satisfied with the data I had. Again, once presented — as an engineer would — with better data, we use better data.”

Welcher frames the change as standard engineering practice while conceding it is not insignificant.

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Quote

“You do.”

Welcher agrees with the timing sequence posed by Alessi: under the revised range, part falls after the device lock. Elsewhere, Welcher disputed that the change was consequential and maintained the original timing was within measurement variance.

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Direct Judson Welcher - Direct Judson Welcher Hank Brennan 5 highlights 401 lines spoken
Summary

Prosecution expert Judson Welcher presents accident reconstruction and biomechanical analysis, including vehicle data, photogrammetric analysis of Ring doorbell video, arm-laceration consistency with Lexus tail-light geometry, and hard-surface fall fracture tolerance; his ultimate opinion that Read's Lexus struck O'Keefe was stricken.

Highlights (5)
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“I have no dog in this fight. I don't, quite frankly, care. What I'm doing is trying to do a good engineering job, which is looking at the data and drawing sound principles and sound conclusions from the data.”

Welcher establishes his claimed objectivity and data-driven methodology for the jury.

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Quote

“So from the maximum point it pulled forward to where it backed up again — that was 34 feet forward, then a total of 53 back, total travel distance of 87 feet. So went all the way forward where it stopped. It then backed up 87 feet. And when the Techstream data stopped, it's still moving. It is still moving about 23 miles an hour, and you're still at 74% throttle and 3,300 revolutions per minute on the tachometer RPM gauge.”

Key finding about the second triggering event — the Lexus was accelerating rapidly in reverse when the data window ended.

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Quote

“The location and orientation of the laceration on John O'Keefe's right forearm and arm are consistent with the geometry and orientation of the right tail light of the Read 2021 Lexus LX 570.”

Welcher testified that the right-arm laceration location and orientation were consistent with the right tail light's geometry and orientation.

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Quote

“What the data is showing is that even at a fall height as low as 40 inches onto a hard surface, you can get fairly severe skull fractures.”

Welcher testified that hard-surface falls as low as 40 inches can produce severe skull fractures.

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Day 22

Direct Judson Welcher - Direct (Continued) Judson Welcher Hank Brennan 4 highlights 31 lines spoken
Summary

Welcher concludes direct examination with opinions that tail light damage is consistent with a collision if the impact was greater than approximately 8 mph, and that O'Keefe's injuries are consistent with being struck by a Lexus and contacting a hard surface such as frozen ground.

Highlights (4)
Quote

“It is consistent with a collision as long as it's greater than approximately 8 miles an hour.”

States the greater-than-approximately-8-mph condition for his consistency opinion.

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“That it is consistent with being struck by a Lexus and ultimately contacting a hard surface such as frozen ground.”

Core prosecution opinion linking O'Keefe's injuries to a vehicle strike followed by ground impact.

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Quote

“So, when you have glancing contacts, you can have much higher speeds without a lot of damage to the car because you're only in momentary contact and it's a glancing type hit.”

Explains the biomechanical basis for limited vehicle damage despite a potentially injurious impact.

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“Yes, you could definitely have this type of impact and not have anything beyond, say, red marks to the lower extremity.”

Directly addresses the defense argument that absence of leg fractures undermines the vehicle-strike theory.

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Cross Judson Welcher - Cross Judson Welcher Robert Alessi 4 highlights 651 lines spoken
Summary

Defense attorney Robert Alessi cross-examines prosecution expert Dr. Judson Welcher, challenging his methodology, potential confirmation bias, the absence of force calculations for the arm injuries, and the financial relationship between his firm Aperture and the Commonwealth.

Highlights (4)
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“I don't quite frankly care whether it's new or not. I just care what's in the data. Whether it's new, old, I don't care. It's not relevant to what I'm doing.”

Welcher dismisses concern about Burgess's mid-trial amended report, which Alessi uses to suggest the prosecution team was generating new analysis during trial.

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Quote

“I have certainly done amended analysis. Only certain courts and certain legal systems require reports. But for example, rebuttal — analyzing testimony that comes up in court, getting trial transcripts — I very frequently have come up with new analysis during the trial.”

Welcher distinguishes amended analysis from amended reports but cannot cite a single case where he submitted an amended report mid-trial.

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“Correct. We don't have that level of certainty. We have that the height and geometry matches.”

Welcher concedes he cannot say with certainty that O'Keefe's head was positioned to be struck by the spoiler, undermining the eye laceration theory.

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“We don't have enough information to determine that.”

Welcher admits he cannot determine how long the arm needed to maintain contact with the tail light to produce the observed wounds — a core gap in the prosecution's injury mechanism theory.

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Redirect Judson Welcher - Redirect Judson Welcher Hank Brennan 3 highlights 13 lines spoken
Summary

On brief redirect, Brennan elicited that Welcher did not use Trooper Paul's report or conclusions and used a photograph only as a demonstrative. Welcher also distinguished the autopsy information he considered—injury descriptions and blood, trauma, and hypothermia—from Scordi-Bello's accident, undetermined, or homicide conclusions.

Highlights (3)
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“I did not use his report at all. It was simply limited to the use of the photo to show a different demonstrative issue.”

Directly rebuts the cross-examination suggestion that Welcher borrowed from Trooper Paul's work.

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Quote

“No, I wouldn't take a person like that — opinion for that.”

Welcher distances himself from the medical examiner's cause-of-death conclusions, asserting that biomechanical analysis requires different expertise.

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Recross Judson Welcher - Recross Judson Welcher Robert Alessi 2 highlights 5 lines spoken
Summary

On recross, defense attorney Alessi confirms that Welcher considered selected highlighted portions of Dr. Scordi-Bello's final diagnosis in the autopsy report; Welcher maintains that cause and manner of death were separate from those portions.

Highlights (2)
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“The important things that I was looking at are the underlined or highlighted, which is why I highlighted them.”

Welcher explained that he considered the underlined or highlighted final-diagnosis findings while distinguishing them from the separately listed cause and manner of death.

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Quote

“Correct.”

Confirms that Welcher considered the highlighted portions of the autopsy report; he had distinguished those portions from cause and manner of death.

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Day 23

Cross Judson Welcher - Cross (Continued) Judson Welcher Robert Alessi 4 highlights 207 lines spoken
Summary

Defense attorney Alessi continues cross-examination of prosecution expert Welcher, challenging his photogrammetry methodology, Ring camera analysis, vehicle suspension measurements, and the significance of TechStream vehicle data.

Highlights (4)
Quote

“Nope. But we have videos from both of them and scans of the scene.”

Welcher concedes he doesn't have the model numbers for either Ring camera used in his photogrammetry analysis.

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Quote

“I don't know. We were matching the photos. So I don't care what the numbers are. I care that the height is the same.”

Welcher explains that his method was photo-height matching rather than reliance on a suspension-setting number; the exchange also leaves the January 29 setting unknown and the source photographs two days later.

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Quote

“No, the impact didn't register the event. As I pointed out, the trigger — the trigger was from when the accelerator pedal went to 30%... So, the TechStream will never register an event even if you hit a wall at 100 miles an hour — necessarily.”

Critical concession that TechStream data cannot confirm a collision occurred — it only records acceleration/braking events, not impacts.

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Redirect Judson Welcher - Redirect Judson Welcher Hank Brennan 4 highlights 14 lines spoken
Summary

Prosecutor Brennan conducts redirect of Dr. Welcher addressing camera replacement, suspension, force distribution, encrypted communications, and confirmation bias challenges raised during cross.

Highlights (4)
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“Absolutely not. It would have shown up as increased error when we overlaid the point clouds onto the photos— or the point clouds onto the video. If it was an error, it would have showed an error.”

Directly addresses the camera replacement challenge — Welcher explains the methodology has a built-in error check

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Quote

“So when you look at the failure loads, it depends on what you're doing it with. If I hit you with a 5-lb 2x4 or a 5-lb pillow, they're both 5 lb, but you'd much rather get hit by the pillow than the 2x4.”

Welcher reframes the force calculation challenge by explaining distributed vs concentrated loads, undermining the bone fracture threshold numbers from cross

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Quote

“No. Again, these are direct readings from the vehicle. Again, that speed on this here— you have to correct for the slippage, which I do later on the slide, but that is a direct reading from what the speedometer is seeing.”

Welcher characterizes the displayed reported speed as a direct vehicle reading, while noting that it requires a later slippage correction; the testimony concerns the raw reading rather than whether a collision occurred or the broader analysis.

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Recross Judson Welcher - Recross Judson Welcher Robert Alessi 2 highlights 10 lines spoken
Summary

Defense attorney Alessi conducts a brief recross challenging Welcher's confirmation-bias defense by establishing that Welcher could not identify a slide or document presented to the jury expressly showing the alternative hypothesis of no contact between the Lexus and O'Keefe.

Highlights (2)
Quote

“So theoretically, my confirmation bias starts with a bias that it didn't happen.”

Welcher's attempt to defend his methodology by invoking a null-hypothesis approach; he later says he did not include everything in the presentation and answers no when asked whether a slide or document presented to the jury expressly showed the no-contact alternative.

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