Expert Witness Blog

In the landmark case of United States v. Yates, No. 11-16093 (11th Cir. 2013), the role of the Fish Expert Witness was central to the dispute over the prosecution of a commercial fisherman charged with federal offenses for harvesting and disposing of undersized red grouper in the Gulf of Mexico.

Background and Parties

John L. Yates, captain of a commercial fishing vessel, was prosecuted by the United States government for violating 18 U.S.C. § 2232(a) and 18 U.S.C. § 1519. The charges stemmed from allegations that Yates knowingly harvested red grouper below the minimum legal size and subsequently ordered the disposal of these fish to prevent their seizure by federal authorities. The government asserted that Yates’s actions constituted both the destruction of evidence and obstruction of a federal investigation.

In the recent case of USA v. Suzanne Ellen Kaye, No. 23-11423 (11th Cir. 2024), the admissibility and role of an Internet Expert Witness became a central issue in evaluating alleged criminal threats made via social media platforms. This case provides a clear illustration of the courts’ approach to expert testimony related to internet communications and the application of Daubert standards in federal criminal proceedings.

Background and Facts

Suzanne Ellen Kaye was charged with two counts of transmitting threats in violation of 18 U.S.C. § 875(c), based on videos she posted to Facebook, Instagram, and TikTok. The prosecution alleged that Kaye’s statements in these videos constituted “true threats” not protected by the First Amendment. The case focused on whether the content and context of Kaye’s online communications met the legal threshold for criminal threats.

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In the pivotal case of Virginia International Gateway v. City of Portsmouth, 829 S.E.2d 199 (Va. 2019), the Supreme Court of Virginia addressed the admissibility and impact of testimony from an International Real Estate Valuation Expert Witness in a high-stakes property tax assessment dispute. This case provides critical guidance on the qualifications required for expert witnesses in real estate valuation, especially in matters involving complex, internationally significant properties.

Background and Parties

Virginia International Gateway, Inc. (VIG), the operator of a major marine terminal in Portsmouth, Virginia, challenged the City of Portsmouth’s 2015–2016 real and personal property tax assessments. VIG contended that the City’s assessments substantially exceeded the actual fair market value of its property, resulting in an unjustified tax burden. VIG filed separate applications to correct both the real estate and personal property assessments, which were consolidated for trial.

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In the property dispute of White v. LeClerc, Rhode Island Supreme Court 1982, the court’s assessment of damages for unauthorized tree removal hinged on the competing testimony of a qualified Trees Appraisal Expert Witness. This case exemplifies the critical role of expert valuation in determining compensation for lost trees and the judicial scrutiny applied to expert methodologies.

Background and Parties

Plaintiffs, owners of a residential property, alleged that defendant Alfred LeClerc trespassed by directing his agent to remove four mature oak trees from their land. The defendant admitted to ordering the removal as part of landscaping and pool installation. The central issue was the appropriate measure of damages for the loss of these trees, which plaintiffs contended were valuable both for their age and contribution to the property’s aesthetics.

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In the landmark case of Williams et al. v. Continental Oil Co, 215 F.2d 4 (10th Cir. 1954), the role of the Mineral Interests Expert Witness was pivotal in resolving complex disputes over subsurface oil rights and well trajectory in Seminole County, Oklahoma. This case exemplifies the critical impact of expert testimony in mineral interest litigation, particularly where technical evidence and interpretation are central to the court’s determination.

Background and Facts

In the recent case of Wingate, E. v. McGrath, D., Pennsylvania Superior Court 2025, the Pennsylvania Superior Court addressed the pivotal role of a Business Valuation Expert Witness in a contentious shareholder dispute. The case provides a compelling illustration of how courts evaluate the reliability and admissibility of expert testimony under Pennsylvania law, with direct implications for the outcome of complex business litigation.

Background and Parties

The dispute arose between Elaine Wingate, a minority shareholder, and Daniel McGrath, the majority shareholder and managing officer of a closely held corporation. Wingate alleged that McGrath had engaged in oppressive conduct and sought a judicial determination of the fair value of her shares following her forced removal from the company. Central to the litigation was the accurate valuation of the business, which would determine the amount owed to Wingate for her equity interest.

Davis v. Globe Machine Manufacturing Co.

A notable case involving a Machine Guarding Expert Witness is Davis v. Globe Machine Manufacturing Co., decided by the Washington Supreme Court in 1984. This case centered on workplace safety, specifically the adequacy of machine guarding on industrial equipment, and provides a clear example of how expert testimony can shape the outcome of litigation involving industrial accidents and alleged product defects. The full opinion is available at Davis v. Globe Machine, 102 Wn.2d 68 (1984).

Background and Facts

Pedro Fidalgo & others v. Columbus McKinnon Corporation

A recent case involving a Latches & Fasteners Expert Witness is Pedro Fidalgo & others v. Columbus McKinnon Corporation, decided by the Massachusetts Court of Appeals in 2002. The case citation is Pedro Fidalgo & others v. Columbus McKinnon Corp., 56 Mass. App. Ct. 176 (2002).

Background and Facts

Davis v. Sig Sauer, Inc.

A recent legal case involving an Ergonomics Expert Witness is Davis v. Sig Sauer, Inc., decided by the United States Court of Appeals for the Sixth Circuit in January 2025. The case citation is Davis v. Sig Sauer, Inc., No. 24-5210 (6th Cir. 2025).

Background and Parties

In the case of E²G v. Ferrellgas, No. 2:22-cv-01234 (D. Utah Dec. 19, 2023), the testimony of a Vibration Analysis Expert Witness was pivotal in diagnosing and resolving issues related to high vibration levels in vertical pumps used in liquid natural gas (LNG) service.

Background of the Case

In October 2021, Ferrellgas installed vertical pumps with 25-stage impellers to handle LNG operations. Initially, the pumps produced higher pressure and flow than required, leading to operational adjustments that resulted in poor motor reliability. In January 2022, two stages were removed, reducing the impellers to 23 stages. A tuning plate was added between the motor base and discharge head to decrease the structural natural frequency of the motor-pump assembly. While vibration amplitudes decreased, in November 2023, one pump exhibited increased vibrations and noise, leading to inspections that revealed wear on the pump shaft and throat bushing.