Accident reconstructionist
Expert class library · Personal injury · Either side
Reconstructs how a vehicle collision or other accident happened, including speeds, positions, and timing. Uses physical evidence, vehicle data, and physics to test competing accounts.
What this expert is retained to answer
- How did the collision happen, and in what sequence?
- How fast were the vehicles traveling, and where were they at impact?
- Could either driver have perceived and avoided the hazard in time?
- Was the physical damage consistent with each party's account and with the claimed injury mechanism?
Methods
- Momentum and energy analysis
- Event data recorder download
- Scene and crush measurement
- Time-distance analysis
- Simulation software
How the testimony is attacked
- Untested mechanism theories. A reconstruction theory that cannot explain the mechanism or be confirmed by testing or simulation is vulnerable. Sims upheld exclusion of a fuel-tank displacement theory on that basis.
- Insufficient physical data. Opponents point to missing measurements, uninspected vehicles, or no speed estimate. Puga held such gaps went to weight where the opinion rested on many other observed facts.
- Merely adopting another expert's work. An expert who only co-signs a colleague's analysis adds nothing reliable. Kim rejected that attack because the expert applied his own reconstruction and biomechanics analysis.
- Investigating officer qualifications. Police investigators are often offered as reconstruction or causation experts. Puga reviewed cases admitting officers whose opinions rest on sufficient physical evidence and distinguished one where the officer could not place the vehicle's lane.
- Dependent opinions fall with the foundation. Design or causation opinions built on an excluded reconstruction theory are excluded too. Sims affirmed exclusion of a co-expert's opinion that relied on the inadmissible theory.
What the public record shows
A deliberately narrow CourtListener search, "accident reconstruction" AND speed AND (Daubert OR "Rule 702"), returned 148 opinions filed since 2015, as of October 2, 2026; broader searches return more. Three that show how courts handle this class of testimony:
| Outcome | Case | Court | Why |
|---|---|---|---|
| Limited | Sims v. Kia Motors of America, Inc.839 F.3d 393 | 5th Cir. 2016 | The Fifth Circuit upheld exclusion of the portion of a reconstruction expert's testimony claiming the fuel tank dropped during the crash, because he could not identify the mechanism or recreate it by simulation, along with a co-expert's opinion that depended on it. |
| Admitted | Puga v. About Tyme Transport, Inc.922 F.3d 285 | 5th Cir. 2019 | The Fifth Circuit affirmed allowing an investigating trooper to give causation opinions grounded in scene observations, tire marks, witness interviews, and another expert's reconstruction, treating his failure to estimate speed or inspect the truck as a weight issue. |
| Admitted | Kim v. American Honda Motor Co.86 F.4th 150 | 5th Cir. 2023 | The Fifth Circuit held the trial court did not abuse its discretion in admitting a biomechanical engineer and accident reconstructionist who applied reconstruction, biomechanics, and occupant kinematics himself rather than merely co-signing another expert. |
Each case links to the free opinion text on CourtListener.
Under amended Rule 702
Since December 1, 2023, Rule 702 says expressly that the party offering an expert must show the court it is more likely than not that the testimony meets each requirement: that it rests on sufficient facts or data, uses reliable methods, and reflects a reliable application of those methods to the case. Questions about the basis of an opinion are no longer automatically matters of weight for the jury. For how the circuits have applied the amendment, see the Rule 702 tracker, which follows each court of appeals; for what that means for preparing or attacking this class of expert, see the guide on amended Rule 702.
Related classes
Guides
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Last reviewed October 2, 2026. How this page is built: rulings are found by searching court opinions on CourtListener, and each one is read in the opinion before it is summarised here; outcomes are labelled by what the court did with the expert's testimony. No individual expert is named. This page summarises public decisions for orientation and is not legal advice; read the opinion before relying on any ruling.