Expert Witness Profiler

Tag: methodology

  • Human Factors Expert Allowed to Opine on Foreseeable Behavior 

    Human Factors Expert Allowed to Opine on Foreseeable Behavior 

    This is a strict products liability and negligence case against Adams, the manufacturer of a plastic Adirondack chair that failed and rendered Ronald Scanlan a quadriplegic.

    The Defendant filed motions to exclude opinions of three of the Plaintiff’s expert witnesses: Russell Dunn, Clifford Tribus and Joellen Gill. The Plaintiff filed a motion to exclude opinions of the Defendant‘s expert witness, Dr. David Jones. 

    Economics Expert Witness

    David DeHaven Jones has over 40 years of experience in Economics and Forensic Economics. He earned his BA from the College of Wooster in 1966, and his MA and Ph.D. from Indiana University in 1968 and 1975, respectively.

    Among other roles, Jones served as a Professor of Economics at the
    University of St. Thomas and as the Director of Policy Analysis at the Minnesota Department of Economic Development. He has authored numerous publications, including “A Note on Life Expectancy and Mortality Adjustment,” Journal of Legal Economics.

    Want to know more about the challenges David DeHaven Jones has faced? Get the full details with our Challenge Study report.

    Chemical Engineering Expert Witness

    Russell Franklin Dunn is a Ph.D. chemical engineer, who has spent his career working in plastics manufacturing and teaching plastics engineering and safety at Vanderbilt University.

    Discover more cases with Russell Dunn as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Spine Surgery Expert Witness

    Clifford Boehe Tribus is a fellowship-trained, board-certified spine surgeon. He is a graduate of Johns Hopkins Medical School. His fellowship training was in spine surgery. He has been a professor of neurosurgery and orthopedics at the University of Wisconsin Medical School for over 30 years.

    Get the full story on challenges to Clifford Tribus’ expert opinions and testimony with an in-depth Challenge Study.

    Human Factors Expert Witness

    Joellen Gill attended Georgia Tech and Wright State Universities for her undergraduate work, earning a BS in human factors engineering in 1979. Her nearly four-decade career includes 15 years in aerospace and national defense industries as a human factors engineer specializing in safety and risk management.

    Gill started part time at ACS in 1994 after completing a master’s degree in engineering, accepted a full-time position in 2005, then, after obtaining certification as a Human Factors Professional, was lead engineer on her first case just a year later. She is also a licensed tribometrist and a Certified Safety Professional.

    Want to know more about the challenges Joellen Gill has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    David Jones

    The Plaintiff sought to exclude Jones’ testimony regarding the “mortality adjustment” and “worklife adjustment” applied to reduce the Plaintiff’s future damages.

    Jones’s worklife adjustment to the Plaintiff’s future earning capacity is improper under Wisconsin law. To calculate the Plaintiff’s lost future earning capacity, the finder of fact must determine how many years the Plaintiff is expected to work and then assess the Plaintiff’s earning capacity for those years. For example, it would not make sense for the jury to determine that the Plaintiff could have worked until age 65, but then to reduce his earning capacity based on the likelihood that he would not be working at age 65. Jones’ “potential earnings loss” table reduced the Plaintiff’s potential earnings in each year based on a probability that the Plaintiff would not be working.

    That necessarily underestimated the Plaintiff’s future earnings in the years that the jury decided the Plaintiff likely would be working. The Court granted the Plaintiff’s motion to exclude evidence of Jones’ worklife expectancy opinions as irrelevant and confusing to the jury.

    The Court also excluded Jones’ “mortality adjustment” opinions for similar reasons. To support an award of future health care expenses under Wisconsin law, (1) there must be expert testimony of permanent injuries, requiring future medical treatment and the incurring of future medical expenses; and (2) an expert must establish the cost of such medical expenses.

    Russell Dunn

    The Defendant contended that Dunn’s opinions are not reliable because he relied solely on testing that ATS performed on the chair. This argument has no merit; an expert is entitled to base his opinion on reports or data generated by another.

    The Defendant next argued that Dunn’s opinions related to risk management lacked sufficient scientific and factual foundation because he relied on two documents when forming these opinions and excluded consideration of the Defendant’s quality assurance standard operating procedures.

    At trial, the Defendant will have the opportunity to cross-examine Dunn regarding the documents he did or did not consider when forming these opinions.

    Next, the Defendant argued that Dunn’s alternative design proposals are not supported by sufficient facts or data or are not the product of reliable principles and methods. However, the Court found that Dunn’s report was sufficient to place the Defendant on notice that the Plaintiff may argue that the addition of antioxidants to the chair’s polymer is a safer alternative design.

    The Defendant argued that Dunn’s opinions on the root cause of the chair’s failure are not reliable because he failed to consider the Plaintiff’s intoxication at the time of the accident. The fact that an alternative explanation or contributing cause existed did not make Dunn’s opinion unreliable.

    The Defendant argued that Dunn’s opinions related to the Defendant not meeting the outdoor furniture industry’s standard of care were not supported by sufficient facts or data. Dunn was entitled to rely on the representative’s sworn testimony to conclude that the Defendant did not test for oxidative degradation. Therefore, the Court cannot conclude Dunn was wrong in relying on the information the Defendant produced in discovery.

    Clifford Tribus

    The Defendant argued that the Court should exclude the Plaintiff’s expert Clifford Tribus because he was not timely disclosed as a principal expert and was improperly designated as a rebuttal expert.

    Tribus’ report rebuts the Defendant’s biomechanical expert’s conclusion that the severity of the injury indicates the Plaintiff must have been in motion when the injury occurred. Tribus was properly designated as a rebuttal expert.

    The Defendant also argued that Tribus’ opinions are not based on sufficient facts or data and are unreliable. Tribus testified that he relied on the Plaintiff’s CT scan and MRI imaging to determine that a low velocity fall could have caused the Plaintiff’s injuries; he did not review any scholarly publications or perform additional research. This is despite the fact Tribus wrote in his report that he had reviewed literature regarding Diffuse Idiopathic Skeletal Hyperostosis (DISH). 

    Moreover, Tribus’ repeated statements that he formed his opinion based on a “generic approach” to DISH injuries does not explain the “methodologies and principles” underlying his opinion in this specific case. Further, though Tribus stated in his opinion that “the literature demonstrates” that DISH patients could suffer severe consequences from slow falls, his testimony reveals that he could not identify any piece of “literature” upon which he relied to form this opinion. That calls into question the reliability of his conclusions. The Court cannot determine if the “literature” on which Tribus relied is sufficient because Tribus does not identify that literature.

    Joellen Gill

    The Defendant contended that Gill is not qualified as a chair designer and cannot opine about the chair’s design.

    Gill never opined about how the Defendant could remedy the alleged hazards of the chair by changing the physical design of the chair. Gill did opine about possible warnings that the Defendant could have used to reduce the risk inherent in the design, using her knowledge of human behavior. But the presence or absence of a warning label has nothing to do with the physical design of the chair. Gill did not opine on chair design, so whether she is qualified to opine on chair design is irrelevant. Because the Defendant provided no other basis for exclusion, the Court denied the Defendant’s motion to exclude with regard to these opinions.

    The Defendant also argued that Gill did not consider any facts outside of the Plaintiff’s counsel’s version of events. 

    Gill’s opinion is that the Plaintiff’s decision to sit on the chair arm was foreseeable human behavior. Gill elaborated in her deposition that her “opinions are focused on were the actions that were engaged in by this person who was injured, were they consistent with foreseeable human behavior. And, in this case, somebody sitting on the arm of a chair to facilitate a conversation is—it was certainly foreseeable behavior.”

    The Plaintiff’s state of mind or motivations—that is, why he chose to sit on the chair arm—are not encompassed in Gill’s opinion about whether the decision to sit on the arm of a chair is foreseeable human behavior. So the Plaintiff’s decision-making process and whether that decision-making process was impaired by his intoxication are not relevant to Gill’s opinion that his actions were consistent with the foreseeable behavior of an outdoor chair user.

    Held

    • The Court granted the Plaintiff’s motion to exclude portions of Dr. David Jones’ opinions. 
    • The Court denied the Defendant’s motion to exclude portions of Dr. Russell Dunn’s opinions. 
    • The Court granted the Defendant’s motion to exclude Dr. Clifford Tribus’ opinions.
    • The Court denied the the Defendant’s motion to exclude Joellen Gill’s opinions. 

    Key Takeaway

    The expert must explain how that experience leads to the conclusions reached, why that experience is a sufficient basis for the opinion, and how that experience is reliably applied to the facts.

    Case Details:

    Case Caption: Scanlan V. Adams Manufacturing Company
    Docket Number: 2:22cv586
    Court Name: United States District Court, Wisconsin Eastern
    Order Date: February 24, 2026
  • Mechanical Engineering Expert Not Allowed to Opine on Zippers

    Mechanical Engineering Expert Not Allowed to Opine on Zippers

    Plaintiff Amcor Flexibles North America, Inc. (Amcor) brought this action against Defendant Reynolds Packaging, LLC (Reynolds), asserting claims for negligence, indemnification, and breach of warranty arising out of Amcor’s purchase from Reynolds of allegedly defective zippered, food-storage pouches.

    Reynolds sued the Third-Party Defendant Reynolds Presto Products, Inc. (Presto), the manufacturer of the zipper component used in the pouches, for breach of implied warranty.

    Reynolds offered the opinion of Matthew Furrer in support of its contention that Presto’s zippers were defective.

    Mechanical Engineering Expert Witness

    Matthew J. Furrer is the owner and a primary consulting engineer at Krenz Engineering. He holds a bachelor’s degree and master’s degree from the Mechanical Engineering department at the University of Wisconsin – Madison.

    Discover more cases with Matthew Furrer as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Discussion by the Court

    Amcor manufactures flexible packaging materials, many of which are used to package food products. Tru Fru, one of Amcor’s customers, ordered zippered, food-storage pouches for its chocolate-covered frozen and/or freeze-dried fruit products. Amcor subcontracted with Reynolds to produce the pouches from the film Amcor provided, and Reynolds purchased the plastic zippers that made the pouches resealable from Presto. Reynolds incorporated the zippers into the pouches and then shipped the finished product to co-packers to be filled with Tru Fru product. During the packaging process, a fuzz-like plastic contaminant known as “angel hair” was found in some of the packages.

    Furrer, a mechanical engineer, did not dispute the finding of the joint investigation that the zipper guide originally on the Hudson-Sharp machine was a cause of the angel hair in the finished Tru Fru product. In fact, Furrer did not analyze the zipper guide and made no attempt to determine whether the machine caused the problem. Nor did Furrer dispute that once the Hudson-Sharp zipper guide was modified, no further angel hair contamination was noted. Instead, Furrer’s opinion was that there could have been another cause of the angel hair contamination, namely, that the zippers provided by Presto were defective in that they had angel hair accumulations at the time the zipper material was delivered to Reynolds and before it was incorporated into the pouches.

    Analysis

    Regardless of whether Furrer is qualified by his education, training, or experience, the Court is satisfied that Reynolds has failed to establish by a preponderance of the evidence that his methodology is reliable or that the proffered testimony is relevant.

    To begin with, Furrer’s methodology involved conducting a test that had little resemblance to the actual operation of the machines used to produce the pouches, and the test was conducted on zipper material that had previously been rejected by Reynolds as nonconforming because of the presence of strings.

    It is undisputed that this rejected material was not used to produce the pouches that were delivered to Tru Fru’s co-packagers and were later found to contain the angel hair contaminant. This is not a test that could produce a reliable answer to the question of whether the zipper material actually used to produce the Tru Fru pouches was defective.

    Held

    The Court granted Presto’s motion to exclude the expert opinion of Matthew Furrer.

    Key Takeaway

    Furrer is unable to offer more than speculation as to whether the zipper material actually utilized in the Tru Fru pouches was defective. In other words, his opinion that it could have been defective is insufficient to assist the factfinder. It is therefore irrelevant and thus inadmissible.

    Case Details:

    Case Caption: Amcor Flexibles North America Inc V. Reynolds Packaging LLC
    Docket Number: 1:23cv1306
    Court Name: United States District Court, Wisconsin Eastern
    Order Date: June 03, 2026
  • Law Enforcement Expert Was Not Allowed to Opine on the Officers’ Intent

    Law Enforcement Expert Was Not Allowed to Opine on the Officers’ Intent

    This case arises from officers’ alleged excessive use of force during an investigation of a 911 call regarding Plaintiff Henry Barnhill (“Barnhill”).

    Defendants City of Hemet, Brett Maynard, Joshua Bishop, Pedro Aguila, Douglas Klinzing, Jamie Gonzalez, and Catherine Tipton (collectively, “Defendants”) filed two motions (1) to exclude certain opinion and testimony of expert Dr. Ryan O’Connor and (2) to exclude certain opinion and testimony of expert Roger Clark.

    Emergency Medicine Expert Witness

    Ryan Scarritt O’Connor is a 20-year attending ER physician who is board-certified and has completed several clinical rotations in neurology, ophthalmology, biomechanics, general surgery, and traumatic medicine, among others, and holds a Master of Science in criminalistics with education in crime scene reconstruction.

    Discover more cases with Ryan O’Connor as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Law Enforcement Expert Witness

    Roger Alma Clark is a retired law enforcement professional with 27 years of experience in the Los Angeles County Sheriff’s Department (LASD). He was hired on December 1, 1965, and served until his retirement on March 31, 1993. Throughout his distinguished career, he held several key positions, including six years as a Deputy Sheriff, six years as a Sergeant, and 15 years as a Lieutenant. Roger retired with a California Peace Officer Standards and Training (POST) Advanced Certificate and is a graduate of the POST Command College, class #5, 1988.

    Get the full story on challenges to Roger Clark’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    Ryan O’Connor

    Defendants sought to exclude the opinions of Barnhill’s medical expert, O’Connor, regarding his conclusions that the incident resulted in Barnhill sustaining certain injuries.

    Defendants based their arguments on the fact that (1) O’Connor is an ER doctor, rather than a specialist in ophthalmology; (2) O’Connor relied more heavily on the officers’ statements as opposed to the video evidence; and (3) O’Connor failed to take into consideration all of Barnhill’s medical history. However, given O’Connor’s education, credentials, and experience, the Court held that Defendants’ concerns speak to the weight, rather than admissibility under FRE 702 and Daubert.

    Roger Clark

    To begin with, Defendants sought to exclude opinions by Barnhill’s police-practices expert, Roger Clark, regarding his “legal conclusions concerning the officers’ use of force, standards within the City of Hemet and the Hemet Police Department, the officers’ mental and emotional states and intentions, interpretations of the videos taken from officers’ body cameras, and all other conclusions and opinions based on Clark’s flawed methodology, which omits important information contained in the footage and is admittedly impermissibly intertwined with Plaintiff’s counsel’s opinions.”

    To the extent that Clark offered legal conclusions, such as that the officers used unreasonable or excessive force during the incident, the Court granted the motion to exclude. Clark was also precluded from opining on the officers’ intent or emotional states and on the medical cause of Barnhill’s injuries.

    However, to the extent that Clark’s testimony was limited to whether the officers’ conduct was consistent with California Peace Officer Standards and Training (“POST”) standards governing the use of force, the Court denied the motion. This basically included determinations based on Clark’s review of the video evidence demonstrating how Barnhill was responding during the incident, which were relevant to whether the officers’ conduct comported with POST standards in light of Barnhill’s actions.

    Held

    • The Court denied Defendants’ motion to exclude the testimony of Ryan O’Connor.
    • The Court granted in part and denied in part the motion to exclude the testimony of Roger Clark.

    Key Takeaway

    In conclusion, a jury could rely on expert testimony as to whether police conduct comported with POST standards.

    Case Details:

    Case Caption: Henry Barnhill V. City Of Hemet
    Docket Number: 5:23cv589
    Court Name: United States District Court, California Central
    Order Date: June 03, 2026
  • Firearms Expert Allowed to Opine on Air Rifle

    Firearms Expert Allowed to Opine on Air Rifle

    This is a products liability case arising from an alleged injury caused by an air rifle. Plaintiff Brian Cornwell (“Cornwell”) ordered an air rifle from Extreme Big Bore Air Rifles on March 25, 2021. After regularly using the rifle for nearly two years, on January 11, 2023, Plaintiff injured himself while attempting to fill the air rifle with compressed air. He sustained an injury to his left thumb.

    Defendants Texas Machine Parts, Danny Duke, and John Wiley filed a motion to exclude Plaintiff’s experts, Kennith Comeaux and William Caster, or, in the alternative, to exclude any testimony from them related to medical causation.

    Firearms Expert Witness

    Kennith R. Comeaux has thirty-five years of experience as a gunsmith. Because of his familiarity with guns, in his other career as a certified ISO 9000 quality auditor, he “was allowed to audit firearms manufacturers and ammunition manufacturers” to determine if the companies could get ISO certified by meeting “an international standard associated with quality that is very similar to OSHA with respect to safety, but for quality.”

    Discover more cases with Kennith Comeaux as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Air Mechanics Expert Witness

    William B. Caster, Jr. holds a certification from the National Balancing Council, “a group that educates and teaches in air balancing and hydronic balancing, which is airflow CFM delivery, pressure, and velocity.” He owns a consulting company for heating, ventilation and air conditioning, airflow dynamics, hydronic testing, and air testing.

    Want to know more about the challenges William Caster has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    A. Kennith Comeaux

    Though Comeaux acknowledged that he is not an expert in gun manufacturing, his experience in being able to quality-audit firearms and ammunition manufacturers underscores his gunsmithing experience.

    Comeaux also relied on sufficient facts and data to reach his conclusions and utilized reliable principals and methods. Importantly, he personally inspected the air rifle as well as consulted an American Society for Testing and Materials (ASTM) manual, looked at the subject air rifle’s owner’s manual as well as the owner’s manuals of other similar rifles, and researched other manufacturer’s diagrams.

    Comeaux also explained his methodology and how it comports with the ASTM and could be replicated by others. His decades-long experience as a gunsmith, combined with the foregoing, allowed the Court to find that Comeaux’s testimony is sufficiently reliable.

    It is also clear that Comeaux’s testimony will assist the trier of fact and is relevant. For example, one line of Comeaux’s report reads: “Further attempts to seat the exhaust valve without removal of the air chamber cap were unsuccessful including lubrication with Teflon oil.” This shows that Comeaux will provide testimony that goes beyond “common sense.”

    Moreover, this sort of testimony is relevant because Plaintiff’s claims are based in the alleged faulty function and design of the valves in the subject air rifle and a replacement valve assembly, and Comeaux’s testimony reflects his personal evaluation of the air rifle and its replacement valve.

    B. William Caster

    Caster’s testimony is based on sufficient facts and data. Like Comeaux, Caster personally inspected the air rifle at issue.

    He conducted research on the relevant parts included in his testing. Moreover, he limited his testing to his discipline, explaining that he did not operate or fill the air rifle during his testing because he “went there to find out if the equipment that [Plaintiff] utilized for filling the gun exceeded the capabilities or burst pressure of the gun.” As to reliable principles and methods, Caster did not conduct explicit testing like Comeaux, but rather researched and observed whether Plaintiff possessed the “tooling to be able to” fill the air rifle’s air tank beyond its PSI specifications. Caster explained that he based his conclusions off “the actual flow chart of the gun from the tank to the valve to the barrel” because “the only point of when air can enter into the chamber is when the valve is released.”

    Considering these circumstances, the Court found that Caster is qualified to testify at trial based on his experience and the nature and formulation of his opinions.

    C. Medical Causation Testimony

    Defendants asked that both Comeaux and Caster be excluded from offering medical causation testimony because they are not medical doctors.

    To the extent either expert anticipates opining on medical causation at the trial of this matter, the Court will foreclose them from offering any such testimony. Neither Comeaux nor Caster are medical doctors.

    Held

    The Court denied Defendants’ motion in limine to exclude the testimony of Kennith Comeaux and William Caster.

    Key Takeaway

    The fact that opposing parties do not agree with the facts relied upon by the experts or their interpretation of those facts does not render their opinions irrelevant or unreliable; challenges related to the basis of any of the experts’ opinions are thus best suited for cross-examination, not exclusion.

    Case Details:

    Case Caption: Cornwell V. Extreme Tactical Components, LLC
    Docket Number: 2:24cv926
    Court Name: United States District Court, Louisiana Eastern
    Order Date: January 15, 2026
  • Accident Reconstruction Expert Not Allowed to Opine on Statutory Violation

    Accident Reconstruction Expert Not Allowed to Opine on Statutory Violation

    On July 13, 2021, Mark DeLeon lost his left arm in a horrendous accident while working the overnight shift at Norfolk Southern’s Burns Harbor Trainyard. This case arises out of that tragic event. DeLeon sued Norfolk Southern under the Federal Employer’s Liability Act seeking recovery for his injuries. He has two theories under FELA: one is for general negligence; the other is for per se negligence under FELA because of an alleged violation of the Safety Appliance Act (“SAA”).

    Norfolk sought the exclusion of three of DeLeon’s experts-Daniel Billington, Colon Fulk, and Jason Engle.

    Accident Reconstruction Expert Witness

    Daniel R. Billington II is an expert in accident reconstruction, including “human factors, visibility, and lighting.” Billington has been doing accident reconstructions for decades and has been permitted to testify in a number of cases. His knowledge has made him a speaker in high demand with many legal and insurance organizations.

    Get the full story on challenges to Daniel Billington’s expert opinions and testimony with an in-depth Challenge Study.

    Railroad Expert Witnesses

    Colon Ray Fulk has over three decades of experience in train operations. Notably, he has worked for Norfolk as a conductor, brakeman, locomotive engineer, and a foreman. He has extensive experience in railroad operations, including safety inspections and investigations.

    Discover more cases with Colon Fulk as an expert witness by ordering his comprehensive Expert Witness Profile report.

    Jason R. Engle has 18 years of experience in the railroad industry, holding both mechanical and transportation positions at multiple railway companies.

    Get the full story on challenges to Jason Engle’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    The Court agreed with Norfolk that the expert reports of Billington, Fulk, and Engle had some improper legal conclusions. Billington, Fulk, and Engle all stated that certain facts constitute a statutory violation and/or negligence. These conclusions “abridge the jury’s role of applying the law to the facts” and, additionally, “usurp the judge’s role of instructing the jury as to the applicable law.”

    The experts will not be allowed to testify as to what satisfies a specific legal standard or what a particular statute or regulation means. However, of course, experts may offer opinions “relevant to applying a legal standard” including testimony “describing sound professional standards and identifying departures from them.”

    1. Daniel Billington

    Billington inspected the site of the incident, took various measurements, and reviewed the footage from the night in question, along with an extensive list of documentary evidence and depositions in this case. He concluded, among other things, that DeLeon struck the air station during the incident in question, that the air station was a close-clearance structure, that the yard was too dark, which posed a danger to employees, and that the bent ladder prevented DeLeon from standing upright, contributing to him hitting the air station.

    Billington took detailed and specific measurements at the railyard, including quantifiable lighting measurements under similar weather and time conditions, and he used his experience and measurements to produce a 3D render of the accident to explain how this tragic and perplexing incident occurred.

    The Court found that Billington was qualified to testify on these topics and that his inspection of the site, reliance on his experience, and review of the documents constituted a proper methodology for an accident reconstructionist.

    One argument Norfolk made that requires special attention is that Billington’s accident reconstruction testimony would not be helpful to a jury. The argument centers on the fact that much of his accident reconstruction is based on the video of the incident, which the jury can watch itself.

    This Court has watched the video of the incident several times. It does not speak for itself. The camera was set up far away from the site of the incident. The video is dark, at times blurry, and in black and white.

    2. Colon Fulk

    Fulk reached various conclusions about the safety of the train yard on the night of the incident, the safety rules Norfolk had in place at the time, and the factors that may have contributed to the accident. He testified about how difficult it is for on-the-ground railmen to know exactly how fast a train is going, especially in nighttime conditions, and opined that it was unsafe for Norfolk to have a rule allowing railmen to board moving trains at all. He testified about many other issues as well, including the dangers posed by the defective ladder and insufficient lighting at the railyard. In reaching his conclusions, he relied not only on the documentary evidence in this case but also on his inspection of the site of the incident.

    Norfolk’s main arguments to exclude Fulk’s opinions are that he lacked a reliable methodology and that his opinions are conclusory. However, the Court found that he has employed a proper methodology for an expert in his field and has explained his reasons sufficiently. He reviewed the records relevant to the incident, and inspected the site of the incident, taking specific measurements and photos, and explained the reasons for his findings in an expert report. This is not an area of expertise where, for example, an expert could point to specific mathematical methodology for his opinion. Fulk’s methodology and opinions (that are not legal conclusions, as discussed above) are proper, and are similar to many other cases in which he has been allowed to testify over the years.

    3. Jason Engle

    Engle’s conclusions include that the bent ladder was unsafe, that the railcar with the bent ladder should not have been in service until the ladder was fixed, and that Norfolk had insufficient, and at times even actively dangerous, safety procedures.

    Norfolk’s argument to exclude Engle is a bit shorter and refers to or mirrors the arguments on Fulk, namely that the expert lacks methodology and has conclusory opinions.

    The only notable difference is that they admit that Engle provided some “additional detail” compared to Fulk. Like Fulk’s expert report, Engle’s expert report exhibited that he has relevant, specialized experience and that he employed a reliable methodology.

    Held

    The Court granted in part and denied in part Norfolk’s omnibus motions in limine to exclude the causation opinions of experts Daniel Billington, Colon Fulk, and Jason Engle.

    Key Takeaway

    Indeed, courts often exclude expert testimony analyzing videos when a jury is just as capable of doing the same thing. While Norfolk argued that Billington brought no more to the table on this issue than a layperson who watches the video, a review of Billington’s report tells a different story.

    Billington relied on his extensive experience in accident reconstruction, used video enhancement techniques to view it more closely, employed the study of kinematics in his analysis, did an in-person inspection of the incident site, and produced a 3D model of the incident to help explain what happened. Billington has provided an analysis that goes way beyond a simple recounting of what he believes the video depicts. And to the extent Norfolk is dubious of Billington’s opinions, that’s what cross-examination is for.

    Case Details:

    Case Caption: Deleon V. Norfolk Southern Railway Company
    Docket Number: 2:21cv224
    Court Name: United States District Court, Indiana Northern
    Order Date: May 19, 2026
  • Construction Expert Allowed to Opine on Causes of Project Delay

    Construction Expert Allowed to Opine on Causes of Project Delay

    P&E is a Kansas-based contractor who entered into a design-build contract with WI RNG Hub North, LLC, for a renewable natural gas production facility in Gillet, Wisconsin (the “Project”) to be completed by February 27, 2023. The Project included construction of two buildings to house process equipment for producing renewable natural gas from dairy cow manure and dryer equipment for producing a fiber by-product. To complete the Project, P&E entered into subcontracts with various companies, including Crescent Power, Bayland Building, Inc. (“Bayland”), and Air Liquide Advanced Technologies U.S., LLC (“Air Liquide”). P&E retained Crescent Power as a material supplier to deliver electrical-power equipment to the Project location, including switchboards and MCCs.

    The Project faced several schedule delays and was completed 175 days behind schedule. Relevant here, P&E alleged that Crescent Power failed to deliver the MCCs on time under their contract. P&E alleged that Crescent Power’s late delivery, combined with its other subcontractors’ contractual failures, significantly delayed the Project’s overall com.

    P&E retained Christopher J. Smocke to review the Project, including its five-page critical path schedule, and offer opinions on the causes of the Project’s delays and resulting damages to P&E. Regarding Crescent Power, Smocke opined that it delivered the MCCs 69 days late, is 41% at fault for the first 140 days of the delay to the Project’s completion, and is responsible for $762,415 of P&E’s total damages.

    Crescent Power filed a motion to exclude Smocke’s opinions under Rule 702 of the Federal Rules of Evidence.

    Construction Expert Witness

    Christopher J. Smocke has worked as a Senior Project Manager, Project Executive, Vice President, and President in various construction companies, for general contractors, and for construction owner’s representative firms. In these roles, he managed budgets and organized schedules for several multi-million-dollar projects. He has also conducted informal mediations where he allocated responsibility between multiple parties in construction project disputes. Further, Smocke has been retained as an expert in three arbitrations and two lawsuits, offering opinions on construction delays and resulting damages.

    Want to know more about the challenges Christopher Smocke has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    A. Qualifications

    First, Crescent Power argued that Smocke lacked the requisite qualifications to offer his opinions. Crescent Power recognized that Smocke has over 50 years of experience in construction project management, but argued that he lacked specific experience or education in conducting forensic schedule analyses and allocating fault pursuant to Association for the Advancement of Cost Engineering (“AACE”) standards.

    The Court concluded that P&E met its burden to show that Smocke is sufficiently qualified based on his significant experience in construction project management.

    B. Reliability of Methodology

    Crescent Power argued that Smocke’s opinions are ipse dixit because he did not conduct a forensic analysis of impacts on the Project’s critical path pursuant to one of the AACE or Society of Construction Law’s prescribed methods.

    In his report, Smocke identified which delays he opined affected the overall completion of the Project based on his review of the case and his experience. For example, he discussed how Crescent Power’s late delivery of MCCs impacted the Project’s overall completion because the switchboards could not be powered up without them, holding up work in both Project buildings and all systems for renewable natural gas production. As P&E pointed out, his discussion mirrors both AACE and Society of Construction Law principles on disruption and delay to construction projects.

    Crescent Power also identified what it considered as “blatant errors” in Smocke’s opinions to demonstrate that his methodology is unreliable. To begin with, Crescent Power argued that Smocke added days to the calendar to reach his opinion that 140 days of delay should be apportioned between Crescent Power, Bayland, and Air Liquide. P&E asserted that Crescent Power simply misunderstood Smocke’s testimony regarding the 140 days. Crescent Power also argued that Smocke failed to consider other delays not caused by Crescent Power in his analysis, but P&E asserted that Smocke correctly considered other delays.

    The Court is concerned, however, with Smocke’s methodology for allocating fault and damages between P&E’s subcontractors. To do so, Smocke took the number of days he determined that Crescent Power missed its required delivery dates (69) and divided that number by the total of late delivery days he determined between Crescent Power, Bayland, and Air Liquide (168) to allocate a percentage of fault to Crescent Power (41%) and ultimately conclude that Crescent Power is responsible for $762,415 in damages.

    C. Sufficiency of Underlying Facts & Data

    Crescent Power also challenged the sufficiency of the facts and data underlying Smocke’s opinions. To begin with, Crescent Power argued that Smocke’s deposition testimony contradicted his opinion assigning 69 late delivery days to Crescent Power. This argument is similar to Crescent Power’s concern over Smocke’s assignment of 140 Project delay days between Crescent Power, Bayland, and Air Liquide. Likewise, the Court reached a similar conclusion and determined that Crescent Power’s concern goes to weight as opposed to admissibility and can be sufficiently addressed on cross-examination.

    Second, Crescent Power again argued that Smocke’s opinion is unreliable because he did not conduct a formal Critical Path Methodology (“CPM”) analysis to establish that the MCCs were on the critical path to the Project. CPM is a a term of art for a method of scheduling and administering construction contracts, and its common use in resolving disputes over excusable-delay claims. The Court also rejected this argument.

    Third, Crescent Power challenged Smocke’s allocation of fault and damages between P&E’s subcontractors on sufficiency grounds two ways: (1) he failed to independently evaluate P&E’s alleged damages; and (2) his allocation was purely speculative and unhelpful to the jury. The Court had already determined that P&E failed to establish that Smocke used a reliable methodology to allocate fault and damages between P&E’s subcontractors.

    Held

    The Court granted in part and denied in part Crescent Power’s motion to exclude the testimony of Christiopher Smocke.

    Key Takeaway

    P&E failed to address Smocke’s formula for allocating fault entirely, let alone explain how it is reliable under Daubert. Because P&E failed to establish this methodology is reliable, the Court did not not permit Smocke to testify to his opinions allocating fault and damages between P&E’s subcontractors based on his self-created formula.

    Case Details:

    Case Caption: P&E Solutions, LLC V. Crescent Power Systems, Inc.
    Docket Number: 6:24cv1209
    Court Name: United States District Court, Kansas
    Order Date: May 08, 2026
  • Security Expert Allowed to Opine on Venue Management

    Security Expert Allowed to Opine on Venue Management

    On July 30, 2022, Plaintiff Gary Stanhope attended a Luke Bryan concert at the Xfinity Theatre in Hartford, Connecticut with friends. The group stood on the asphalt walkway in the general admission area, between Sections 500 and 600, behind the railing separating the lawn from the reserved seating. At approximately 10:00 P.M., Stanhope was assaulted and sustained serious injuries.

    Russell Kolins, Stanhope’s liability expert, opined that Live Nation failed to adequately deploy security, failed to conduct a written risk assessment, and failed to implement adequate security policies and procedures.

    Defendant Live Nation Worldwide, Inc. d/b/a Xfinity Theatre filed this motion to preclude the testimony of Kolins due to his alleged lack of qualification as an expert for (1) large concert venue security; (2) the alleged unreliability of Kolins’ analyses; (3) and the claimed lack of “fit” of his opinions to the facts of the case.

    Security Expert Witness

    Russell David Kolins is a practicing Licensed Private Detective and Security Consultant/Practitioner. He celebrated his 55th year in private practice in August 2024. He is a Board-Certified Criminal Defense Investigator and holds a specialized Bachelor of Science Degree in Security Management. Kolins served three terms as the elected Chairman of the ASIS International Hospitality, Entertainment and Tourism Council.

    Want to know more about the challenges Russell Kolins has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    A. Kolins is Qualified

    Kolins possesses years of experience as a security consultant, holds a certification and bachelor’s degree in Security Management, and served as leadership at the ASIS International Hospitality, Entertainment, and Tourism Security Council. He has been admitted to testify as a security expert in other courts and has spoken on premises security and crowd management.

    Live Nation argued that Kolins has never managed a 22,000-person venue and thus lacked the necessary qualifications. However, the Court held that Kolins does not need to match the exact subtype of security venue.

    B. Kolins’ Methodology is Reliable

    Live Nation argued that Kolins’ expert testimony is not based on an identifiable methodology. It asserted that Kolins’ report and depositions reveal no identifiable methodology for his conclusions and that he did not review any history of prior incidents, did not review crime data, did not read witness depositions, or conduct a site visit.

    The Court found that Kolins explained how his analysis, methodology, and sources met the standard required for him to testify.

    Kolins details his methodology and application to the facts of this case. He utilized authorities such as the American National Standards Institute on Crowd Management and the International Association of Venue Managers. Kolins then details how he took the various factors from the methodology and applied them to the facts at hand. He discussed the foreseeability of crowd density and congestion, as well as alcohol sales. Kolins analyzed the deployment of security personnel and cameras. Kolins also discussed the security planning and protective measures utilized by Live Nation. Finally, he addressed the response of security personnel to crises and incidents. In each section, Kolins references the standards of the security community and analyzes how Live Nation met or did not meet those standards.

    C. Kolins’ Opinions Fit the Facts of the Case

    Live Nation argued that Kolins’ testimony did not fit the facts of the case. Live Nation asserted that the literature cited is dated, and the opinions are boilerplate or general.

    Kolins offered testimony that is important to the issues of negligence. First, he provided an overview of the responsibility of venue managers such as Live Nation and the duties of the facility supervisors regarding security policy and procedures. Additionally, Kolins offered his expert testimony as to the crowd management plans for concert events speaking on the seating arrangement, crowd flow, density of concertgoers, and prior incidents at the concert. Finally, Kolins offered his opinions as to why the security was inadequate including how no security appears to have witnessed the assault itself, the lack of video camera surveillance, and the venue’s responsibility to identify and correct those issues. The Court found that Kolins provided testimony that fits the facts of the case. He described the responsibilities, standards, and alleged failings of Live Nation in connection with the assault on Stanhope.

    Held

    The court denied Live Nation’s motion to preclude the testimony of Russell Kolins.

    Key Takeaway

    An expert’s credentials do not need to be unassailable in order for their testimony to be admissible. Federal Rule of Evidence 702 stated that “if scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.”

    Case Details:

    Case Caption: Stanhope V. Live Nation Worldwide, Inc.
    Docket Number: 3:24cv1342
    Court Name: United States District Court, Connecticut
    Order Date: May 11, 2026
  • Railroad Expert Was Not Allowed to Opine on Hand Brake

    Railroad Expert Was Not Allowed to Opine on Hand Brake

    Plaintiff Justin W. Hedden brought suit against Toledo Peoria & Western Railway, Corp. and its corporate parent Genessee & Wyoming Railroad Services, Inc. for injuries he sustained while working on the railroad.

    Defendants sought an order excluding the opinions of Hedden’s expert, John David Engle.

    Railroad Expert Witness

    John David Engle worked in the railroad industry for decades. Engle has a long history of working in the railroad industry and testifying as an expert witness in FELA matters. He has worked as a carman, technical instructor, training officer, and air brakes superintendent for Norfolk Southern.

    Get the full story on challenges to John David Engle’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    1. Opinion 1: The Hand Brake was Inefficient

    Engle’s first opinion relates to whether the hand brake was “efficient.” The Court found that Engle’s expert report is devoid of any explanation of the methodology he used in reaching his opinion that the hand brake was inefficient. Engle did not inspect the hand brake at issue in this case. Moreover, he did not have a clear theory as to what made the hand brake fail to release when Hedden pulled on it with the brake stick.

    Not only did he lack a sufficiently reliable methodology for this opinion, but what methodology he did have reveals that his testimony would not be helpful to the jury. Engle admitted that his opinion as to the “condition of the hand brake at the time of the incident” relies “solely on Hedden’s description of the hand brake.”

    With no analysis of the hand brake, nor a clear theory as to why it was defective and thus inefficient, Engle’s opinion here boils down to “his belief that Plaintiff’s account of the incident is true.”

    2. Opinion 2: TPW Failed to Inspect and Maintain the Railcars

    In his second opinion, Engle asserted that TPW failed to inspect and maintain the railcars “because the freight car hand brake did not function as intended.”

    First, there is literally no explanation or analysis in Engle’s report as to how he arrived at that opinion. In other words, it is entirely conclusory. He simply stated that, because the hand brake did not function as intended, TPW must have been failing to inspect and maintain the railcars. There is no discussion, for example, of what would constitute proper and regular inspections or an analysis of TPW’s maintenance protocol.

    Second, like the previous opinion, this opinion appears to be wholly based on Hedden’s account of the Incident. It includes no mention or citation to any further investigation by Engle of additional sources, such as TPW’s regular inspection or maintenance practices for railcars. Since his opinion here rests “solely on his acceptance of Plaintiff’s account, the testimony amounted to nothing more than an invitation to the jury to believe his assessment of Plaintiff’s truthfulness” and is thus inadmissible. Third, since the Court has already found that he cannot testify as to whether the brake was efficient or had a defect, and this opinion builds directly on that premise, this opinion now has no admissible support and is thus itself inadmissible.

    3. Opinion 3: The Railcar Involved in the Incident Was Not Properly Identified and Therefore Not Properly Inspected

    Engle’s third opinion is that the freight car involved in the Incident was not properly identified and therefore could not have been properly inspected.

    Engle primarily relied on two key data points in arriving at this opinion. The first is that Hedden and Cardine were told to move the train to the lift, which required them to finish building the train after the Incident and then moved it to its next destination, which made it difficult to figure out which railcar was involved in the Incident. Indeed, he cited to Meyer’s deposition where Meyer admitted that, because he was uncertain as to which railcar was involved, he had to narrow it down to five cars and inspect all of them. The second was that the railcar involved in the Incident was a lighter color than any of the ones Meyer inspected.

    Starting with his methodology, Engle’s reasoning relies on a few different sources, as well as his experience in railyard operations. Engle has experience in building and moving trains in railyards and can testify as to how this can make identifying a particular railcar difficult. While he partially walked back his second reason for this opinion, the opinion still finds support in his first reason: that the continued building and movement of the train made Meyer’s identification of the correct railcar questionable.

    A railcar could match the description and still be the wrong car, and Engle is qualified to explain why. A railyard is a complicated and complex environment. It will be helpful to jurors to have testimony about that environment so the jury can assess whether Defendants did in fact inspect the wrong railcar.

    4. Opinion 4: The Inspection of the Hand Brake was Deficient because Meyer did not use a Brake Stick on It

    Engle’s fourth opinion is that the inspection of the railcar was deficient because Meyer did not use the brake stick Hedden was using, or indeed, any brake stick, on the hand brake as part of the inspection.

    Defendants alleged that Engle lacked sufficient expertise specifically about brake sticks to make this opinion that a proper inspection would have used one.

    Engle’s opinion relates primarily to what constitutes a proper inspection. Engle asserts that a proper inspection would have recreated the conditions of the Incident, which, in this case, would have meant using a brake stick on the hand brake. Even if Defendants are right that Engle is not sufficiently experienced with brake stick usage specifically, that does not mean his opinion that a proper inspection would have used one to recreate the conditions of the Incident is invalid. He has sufficient expertise in railyard operations to testify as to what he believes would have constituted a proper inspection and has provided sufficiently reliable reasoning for this opinion.

    5. Opinion 5: TPW failed to Properly Train Its Employees

    Engle’s last opinion is that TPW failed to properly train certain employees, including Hedden, on how to perform interchange inspections, including specifically on the hand brake and air brake systems and the associated riggings.

    Defendants asserted that Engle’s opinion here is essentially insisting that transportation employees like Hedden be trained on brake systems like mechanical employees and that, in any event, Hedden was not following the safety rules in the events leading up to the Incident.

    Unlike Engle’s opinion regarding the hand brake, his opinion on training “does not require Engle’s physical examination of the hand brake” and Defendants’ arguments do not suggest that his “methodology is unreliable.” Instead, they focus more on his outcome, asserting that the high level of training Engle asserts is necessary is “a nonsensical proposition.” But the Court, as gatekeeper, is “primarily concerned with methodology, not conclusions.”

    Held

    The Court granted in part and denied in part Defendants’ motion to exclude the testimony of John David Engle.

    Key Takeaway

    The Court focuses on principles and methodology, not on the conclusions they generate. The goal of the Rule 702 inquiry “is to assure that experts employ the same ‘intellectual rigor’ in their courtroom testimony as would be employed by an expert in the relevant field.”

    Case Details:

    Case Caption: Hedden V. Toledo Peoria & Western Railway Corp.
    Docket Number: 4:22cv24
    Court Name: United States District Court, Indiana Northern
    Order Date: April 10, 2026
  • Architecture Expert Not Allowed to Opine on the Safety of Retail Escalators

    Architecture Expert Not Allowed to Opine on the Safety of Retail Escalators

    Dick’s Sporting Goods, Inc. (“DSG”) operated a retail location in Lyndhurst, Ohio. After the lone up-down escalator in the Lyndhurst Store stopped working, it was not barricaded though the escalator remained non-operational and stationery.

    Tiffiney Jones contended that she felt a sharp pain in her toe while climbing the stationary escalator and had stepped on a metal wire located on
    the escalator steps, which punctured her sandal and sock.

    Architecture Expert Witness

    Richard L. Zimmerman is currently a licensed, registered professional architect in the State of Ohio, and has been so continuously from 1977 to the present.

    He has reviewed and assessed compliance of a wide variety of buildings and sites with local and state building codes and ordinances, and the norms of accepted and reliable architectural, human factors, engineering, construction, maintenance, and safety industry principles, methods and practices.

    Fortify your strategy by reviewing a Challenge Study detailing grounds for excluding Richard Zimmerman’s expert testimony.

    Discussion by the Court

    A. Zimmerman is not Qualified to Give Expert Testimony

    DSG argued that Zimmerman’s education and experience demonstrated that he is a qualified architect, but an expert’s status as a qualified architect does not necessarily mean that he can testify on the “retail maintenance of escalators, which is the issue in this case.” DSG asserted that Zimmerman’s conclusions that DSG violated the Ohio Revised Code, Ohio Building Code, Elevator Code, and Escalator Code cannot be made without knowledge of the retail standards for maintaining escalators.

    The Court agreed with DSG and found that Zimmerman is not qualified to testify on commercial escalator maintenance and safety. Zimmerman’s qualifications are related to his status as a registered architect and his experience with Ohio Codes, retail locations of escalators, and pedestrian traffic flow.

    His experiences as an architect did not provide a foundation for specialized knowledge on the safety, maintenance, and structural integrity of retail escalators. So, without technical or specialized knowledge of the appropriate and relevant standards to maintain escalators, Zimmerman was unqualified to opine on DSG’s adherence to the standard of care to maintain the escalator.

    B. Zimmerman’s Conclusions Are not a Product of Reliable Methods

    In the methodology’s first step, Zimmerman conducted a fact-finding inquiry by reading the incident report, depositions, and DSG’s internal policies. Zimmerman also reviewed photographs and video surveillance. Notably absent from this factual basis examination are visits to the Lyndhurst Store, inspections of the disputed escalator, modeling, or testing of the escalator. In his second step, Zimmerman reviewed and identified relevant safety standards and provisions of the Ohio Code, which required no data collection, testing, or analysis. Finally, the last step in Zimmerman’s methodology simply applied the facts established in the first step to the various Code provisions identified in the second step. From this application, Zimmerman arrived at the conclusion that DSG failed to maintain a safe premises because Plaintiff attests that there was a sharp object on the escalator. This is a significant analytical jump for Zimmerman to make, and he did not stick the landing.

    DSG contended that Zimmerman’s failure to inspect the Lyndhurst Store, examine the escalator, or test Plaintiff’s footwear resulted in untested and unsupported conclusions.

    The Court agreed with DSG and found that Zimmerman’s testimony is not based on reliable procedures.

    C. Zimmerman’s Opinions Will Not Assist the Trier of Fact

    DSG contended that Zimmerman’s testimony contains no new perspectives to assist the jury because his testimony was based on a simple identification of relevant code language and application to readily available documents, which the jury could do themselves.

    Consistent with the above analysis, the Court found that Zimmerman’s testimony would not assist the trier of fact in resolving this litigation.

    Held

    The Court granted DSG’s motion to exclude the testimony of Richard L. Zimmerman.

    Key Takeaway

    Expert opinions that are not based on site-specific data or a generally accepted modeling but are based on anecdotal evidence with improper extrapolations do not comply with Rule 702 requirements.

    Aside from gathering facts and identifying relevant Code provisions, Zimmerman failed to provide a basis for his conclusions that address where the sharp object was located on the escalator, if the object was caused by DSG’s malfeasance, and whether the sharp object caused Plaintiff’s injuries.

    Case Details:

    Case Caption: Jones V. Dick’s Sporting Goods, Inc.
    Docket Number: 1:24cv619
    Court Name: United States District Court, Ohio Northern
    Order Date: April 07, 2026
  • Law Enforcement Expert Was Not Allowed to Opine on the Suspect’s Flight

    Law Enforcement Expert Was Not Allowed to Opine on the Suspect’s Flight

    Hakim Ledbetter was charged with: attempted possession with intent to distribute 500 grams or more of methamphetamine, 5 kilograms or more of cocaine, and 1,000 grams or more of PCP and aiding and abetting; possession of a firearm in furtherance of a drug trafficking crime; and possession of a firearm by a felon.

    The Government intended to present at trial evidence of Ledbetter’s flight, and “argue that his flight establishes his consciousness of guilt.”

    Ledbetter thus sought to introduce Chuck Rylant‘s testimony “regarding psychological and physiological factors that affect human responses to threatening stimuli,” so that the jury could “understand alternative reasons for flight in situations of perceived threat.”

    The Government moved in limine to exclude Rylant’s testimony, or in the alternative, for a pretrial Daubert Hearing, arguing that his opinion is irrelevant and inadmissible.

    Law Enforcement Expert Witness

    Chuck J. Rylant is a former police officer who has investigated and reviewed crimes of violence—including fights, attacks, and homicides—committed with various weapons.

    He earned a doctorate in clinical psychology in addition to completing numerous master’s level classes in psychology.

    Want to know more about the challenges Chuck Rylant has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    Qualifications

    Rylant is not qualified to testify as to Ledbetter’s psychology. Rylant received his “Psy.D.” degree from “California Southern University,” an exclusively online, unaccredited school. While Rylant purports to be an expert on the psychological and physiological limitations of what humans are capable of, the defense presented nothing to establish that Rylant is trained to evaluate the psychological basis for a suspect’s flight from the police. Most of Rylant’s teaching and lecturing occurred when he had earned only an MBA degree—well before he received his “Psy.D.” in 2020.

    Rylant’s curriculum vitae confirmed that his specialty is limited to police use of force decisions and self-defense. Moreover, Rylant purportedly could not recall in how many federal criminal cases he was qualified to testify as an expert. Although he initially said that his “understanding” was five cases, he then acknowledged it was three. In those cases, he opined only on the decision to use force. Finally, Rylant acknowledged that he had never before offered an expert opinion on the psychological reasons for a person’s flight from police.

    This case does not concern whether police use of force was reasonable, but whether Ledbetter’s flight from police showed consciousness of guilt. In other words, Rylant’s “specialized knowledge” otherwise has nothing to do with Ledbetter or this case. His work on police use of force aside, Rylant has authored two series of books: one titled “How to Be Rich,” and the other, a jiu-jitsu primer.

    Reliability

    According to the Court, Rylant’s “expert report”—which he drafted in an hour—was exceedingly general, including virtually no mention of the facts of this case. Indeed, Rylant testified that he had essentially cut and pasted his Ledbetter report from strikingly similar reports he had prepared for other cases having nothing to do with flight from the police.

    Rylant did not base his “expert” opinion respecting flight from police on reliable methodology. Indeed, Rylant never explained his methodology.

    He never spoke with Ledbetter or anyone else about why Ledbetter fled. He never visited the neighborhood where Ledbetter was arrested. Indeed, although he purported to be uncertain, he apparently has never visited Philadelphia. Rylant offered no studies that he or anyone else conducted about flight from police.

    Fit – Rule 403

    It is apparent that the “fit” of Rylant’s opinion to Ledbetter is poor. He sought to opine that something (which he never clearly identified) other than consciousness of guilt could cause someone in Ledbetter’s circumstances to flee in the manner Ledbetter did. Yet, in forming this opinion, Rylant was ignorant of circumstances that could well have caused Ledbetter to flee from the police. On October 15, 2024, Ledbetter:

    • was in violation of his parole because he had left the state of Georgia
    • effectively possessed three loaded handguns;
    • as a parolee, and a convicted felon, was prohibited from possessing any weapons;
    • was driving a truck containing drugs valued at over $1 million;
    • had previously fled from police when they executed a warrant;
    • had previously been convicted of federal drug charges; and
    • had previously shot someone and been convicted of aggravated assault.

    Rylant then reluctantly acknowledged that this new information could have provided reasons for why someone in Ledbetter’s circumstances would run from police. The potential for prejudice and jury confusion arising from the Government’s “other reasons for flight evidence”—with its attendant cautionary instructions—would plainly outweigh the probative value of Rylant’s unreliable opinion, which he was not qualified to give.

    Rule 704

    Rule 704(b) still prohibits an expert from opining about the “possible” mental state of a Defendant. Accordingly, the Court determined that the defense’s attempt to end-run Rule 704(b) was impermissible.

    Held

    The Court ruled that because Chuck Rylant’s proffered opinion did not pass muster under Rules 702, 704, and 403, he could not testify at trial.

    Key Takeaway

    Although proffered to opine on Hakim Ledbetter’s psychology, Rylant is not and has never been a psychologist. His “Psy.D.” was conferred in 2020 by an unaccredited, exclusively online institution. He appears never to have testified, written, or lectured on the issue he was called to address: the psychology of a suspect fleeing from police. The three federal cases in which he purportedly testified bear no resemblance to Ledbetter. Rylant’s methodology is unknown.

    Although he purported to base his opinion only on generalities, he “revised” that basis and impermissibly strayed into his belief that Defendant lacked mens rea in fleeing from police. Admitting Rylant’s opinion would thus likely open the door to other explanations highly damaging to Ledbetter—about why he fled, as well as cautionary instructions, which would certainly confuse the jury.

    Case Details:

    Case Caption: United States V. Ledbetter
    Docket Number: 2:24cr423
    Court Name: United States District Court, Pennsylvania Eastern
    Order Date: April 02, 2026