Setting the Foundation: Credentials, Scope, and Sources

Karen Read’s Defense team hired accident reconstructionist experts from ARCCA. Their team is Dr. Daniel Wolfe, Dr. Andrew Rentschler, and Scott Klein.

They did not know the defense nor associated parties before involvement in the first trial. Their prior work was independent for testimony in spring/summer 2024, as they were hired by the FBI. However, the jury is not supposed to know this. Nonetheless, many hints abound regading a mysterious “other agency” not local nor state police. They were not retained but were paid by the defense approximately $10K for travel expenses and their time testifying shortly after the first trial.

Dr. Wolfe became ARCCA’s accident reconstruction director in 2024. He’s adequately qualified and you can find his academics, training and experience at ARCCA’s website. 

Scope and Materials Reviewed

In preparation for the first trial, Dr. Wolfe reviewed the following materials: autopsy and crash data reports, photos, videos, Lexus vehicle data. They were to look at the evidence provided and determine whether the damage to the vehicle was consistent with the injuries to John O’Keefe. They had no predetermined theory; they developed their own. They focused on taillight damage consistency with either a cocktail glass thrown at it, or a pedestrian impact.

The cocktail glass test was performed before the first trial, and was also discussed in the second trial. ARCCA team built a pressurized cannon to simulate a glass hitting an exemplar taillight.

The 37 mph speed in which the glass projected was the sweet point and resulted in damage consistent with Lexus taillight damage. Wolfe made it clear that he did not conclude that the glass caused the damage—just that it was plausible.

Now, onto the Retrial: 

The Night of Crash Dummies and Cocktail Glasses: A Courtroom Tale

The courtroom was charged with tension as defense expert Dr. Daniel Wolfe took the stand. By his own testimony, he began as ARCCA’s no-nonsense reconstructionist, uninfluenced by lawyers or media. But by his own admission, in February 2025, he reached out to the defense because of things he had heard in the media. That statement was quickly objected to by Prosecutor Brennan, and sustained and stricken by Judge Cannone.

By March 2025, reports Wolfe, he and his ARCCA team were officially hired for Trial 2. It was James Bond meets courtroom drama—except instead of relevant case files, he brought a textured pot of media optics and a brand‑new job title. They were asked to review  Commonwealth expert material witness Dr. Welcher’s report and analysis.

Dr. Wolfe and his team—organic, sedan‑obsessed scientists—injected velocity (and skepticism) into a Lexus taillight. First, they renewed the presentation of the cocktail glass experiment, once again supporting the Commonwealth’s iteration that the taillight was damaged in this vehicle incident. When the chunks of taillight matched those on Karen Read’s car, Wolfe coyly noted: “Consistent… but not conclusive.”

Prosecution witness Dr. Welcher concluded that the location and orientation of the lacerations on John O’Keefe’s right forearm and arm are consistent with the geometry and orientation of the right rear tail light of Karen Reeds 2021 Lexus.

Then the real show began. Crash‑test dummies, limbs held by harness, a “Rescue Randy” manikin sans integrity, and test speeds ranging from a casual 10 mph to a ballistic 29 mph.

Wolfe staunchly proclaimed the results “inconsistent” with a pedestrian collision—even when the broken taillight looked suspiciously familiar at 24 mph. He waved away troubling variables like arm mass, free trajectory, and debris patterns with a flourish only a seasoned lawyer could love.

Let’s break it down: 

The Hoodie Mystery

The test sweatshirt survived 24 mph impact with no punctures. Wolfe hails this as an inconsistency.

Wolfe didn’t replicate where on the dummy those punctures might have occurred in real life…so, not exactly a slam dunk. The dummy’s arm on this test was unrealistically outstretched rather than placed in a normal human pose, and the arm hit the taillight in a different area.

As prosecution witness Dr. Welcher explained, there are simply too many variables in this type of collision scenario to expect consistent results from a single test. Each trial can produce different patterns of breakage or damage, depending on slight changes in positioning, angle, and movement. Even if you conducted the test 100 times, you might never reproduce the exact injuries or sweatshirt damage observed in this case.

One and done isn’t science—it’s speculation dressed up in lab gear.

Cross-Examination: Brennan’s Reality Check

Brennan exposes that Dr.Wolfe failed part of his certification exam (the practical exam); and lacks pedestrian-specific experience or publications.

Appeals to jury: “Didn’t you just say impact happened at night in bad weather? Yet you omitted pedestrian risk statistics that help the Commonwealth?”

In the first trial, Wolfe provided the defense scripted questions and answers after claiming not knowing anyone on the defense team. 

He also used Signal, (for the first time ever), an app known for secrecy and not retaining conversation records, which was insisted upon by the defense team. Wolfe claimed that he deleted the entire conversation after the first trial, since the trial was over.

I’m just gonna go out on a limb here and assume that Dr. Wolfe heard about the mistrial, and that there would be a second trial. It’s also safe to assume he would be called for the second trial. Maybe Dr. Wolfe just doesn’t have any common sense. 

He flip-flopped on the effect of arm/body mass and harnesses on damage outcomes—once dismissive, then emphatic: “Weight matters!”

The Rekindle: Dr. Welcher’s Methodology

Dr. Judson Welcher of Aperture opted not to use crash‑test dummies in his testing. Why? His goal was simple: show that limb alignment with the vehicle could cause the observed abrasions —without the complications of harnessed physics.

As he stated, he wanted clean, static geometry to build a plausible model of injury location and angle—minimizing distraction from unknown variables.

Dr. Wolfe criticized Dr. Welcher for lack of post impact trajectory in his test. However, it’s impossible to a have post impact trajectory study in Dr. Wolfe’s test due to the harness suspension of the dummy. When pedestians are hit, they aren’t dangling from ropes.  

So—are Crash Test Dummies Actually Useful Here?

In a courtroom context? They can be. But…

ATD crash dummies were developed to evaluate vehicle safety systems—airbags, seat belts—not to mimic pedestrian dynamics or nuances of limb‑only impacts.

They typically represent mid‑size adult males (and only basic female/body types), not weighted, graphed, or positioned for a pedestrian.

Some experts warn that this can lead to unrealistic damage patterns in reconstruction scenarios.

Critics argue that dummies are often “too stiff”—making pedestrian-test results not align with real-world cases.

Their original inventor, Samuel Alderson, certainly built them for seatbelt and airbag testing—not arm-to-tail light torture tests.

Even ARCCA’s case study uses ATDs for things like bus‑seat impacts to judge forces the way Wolfe should have—rigorously—testing a real-world scenario

Crash test dummy results here are suggestive, not determinative. Real physics—that pesky mass × acceleration × force bit—don’t vanish because James Bond’s ATD arm is tethered or missing broken internal diffusers. As the Guardian reminds us: crash test dummies were never made to replicate a pedestrian’s ragged impact—and using them as if they were is, well, a stretch.

Conclusion – Courtroom Carnage, Literally

Key takeaways (briefly told):

Cocktail glass test: Confirmed physical plausibility but didn’t advance proof.

Pedestrian‑simulation tests: At 24 mph, results were eerily similar—yet Wolfe declared them not quite right due to angles, harnessing, and missing internal diffuser damage.

Dr. Wolfe overplays geometry like a playbook and then retreats when his own test setups break his argument. His criticism of Welcher’s “lack of force analysis” quickly evaporates when the courtroom draws attention to real-world complications like harness motion, debris scatter, arm mass, and actual physical data on damage.

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