Expert Witness Blog

​In the case of Valladares v. United States, No. 4:19-CV-02901 (S.D. Tex. 2023), the testimony of a Rescue Expert Witness was pivotal in evaluating the actions of law enforcement during a failed hostage rescue operation.​

Background of the Case

In January 2018, Ulises Valladares was kidnapped from his home in Conroe, Texas, and held for ransom. The FBI tracked the kidnappers to a residence in Houston, where Valladares was found bound and gagged. During the rescue attempt, an FBI agent discharged his weapon, fatally wounding Valladares. Subsequently, Valladares’ family filed a lawsuit against the United States, alleging negligence and wrongful death.​

In the case of Crofts v. Issaquah School District, No. 19-35473 (9th Cir. 2022), the testimony of a School Safety Expert Witness was pivotal in addressing allegations of negligence related to the supervision of a child with special needs.

Background of the Case

The plaintiff, Sandra Crofts, filed a lawsuit against the Issaquah School District after her daughter, A.S., who has special needs, sustained injuries during a school activity. Crofts alleged that the school failed to provide adequate supervision and did not adhere to the individualized education program (IEP) designed to ensure her daughter’s safety. The school district contended that they had followed appropriate protocols and that the injury was an unfortunate accident.

​In the landmark case of Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), the role of a Tires Expert Witness was central to the proceedings and had a profound impact on the standards for admitting expert testimony in U.S. courts.​

Background of the Case

On July 6, 1993, Patrick Carmichael was driving his minivan when the right rear tire blew out, leading to a tragic accident that resulted in the death of one passenger and severe injuries to others. Subsequently, Carmichael and the affected parties filed a lawsuit against Kumho Tire Company, asserting that the tire was defective and that this defect was the proximate cause of the accident. A significant portion of their case relied on the testimony of Dennis Carlson, a tire failure analyst. Carlson intended to testify that, based on his expert opinion, a defect in the tire’s manufacture or design was responsible for the blowout. His conclusions were drawn from a visual and tactile inspection of the tire, coupled with the theory that, in the absence of specific physical signs indicating tire abuse, the failure must have been due to a defect.​

In the case of State v. Lucy Letby, a Failure Analysis Expert Witness played a pivotal role in challenging the convictions of Lucy Letby, a former neonatal nurse accused of harming infants under her care. Letby was convicted in 2023 of murdering seven babies and attempting to murder six others at the Countess of Chester Hospital in the United Kingdom. However, subsequent expert analysis has cast significant doubt on the medical evidence that led to her conviction.

Following her conviction, Letby’s legal team sought the expertise of Dr. Shoo Lee, a renowned Canadian neonatologist. Dr. Lee assembled a panel of 14 international medical experts to conduct an independent review of the cases. This panel meticulously examined the medical records and evidence presented during the trial. Their findings were groundbreaking: they concluded that there was no medical evidence supporting the claim that Letby deliberately harmed or murdered any of the infants. Instead, they attributed the deaths and injuries to natural causes or substandard medical care, highlighting issues such as inadequate staffing, delays in treatment, and misdiagnosis of diseases at the hospital.

One of the critical pieces of evidence during the original trial was the testimony of Dr. Dewi Evans, the prosecution’s lead expert witness. Dr. Evans had cited a 1989 study by Dr. Lee to support the claim that certain skin discolorations observed in the infants were indicative of air embolism, allegedly caused by Letby injecting air into the babies’ bloodstreams. However, Dr. Lee later stated that his research was misrepresented during the trial. He clarified that the signs described were not observed in the cases in question and that diagnosing air embolism based solely on skin discoloration was a “fundamental mistake of medicine.”

In legal proceedings involving driving under the influence (DUI), the testimony of an Alcohol, Drug & DUI Testing Expert Witness can be pivotal in determining the outcome of a case. A notable example is the case of People v. Vangelder, which delved into the admissibility of expert testimony challenging the reliability of breathalyzer tests.

Background of the Case

In People v. Vangelder, the defendant, Terry Vangelder, was stopped by the California Highway Patrol for speeding and subsequently subjected to breathalyzer tests. The initial tests, conducted using a handheld device, indicated blood alcohol concentrations (BAC) of 0.095% and 0.086%. Further tests at the county jail using a different device showed a BAC of 0.08%. Vangelder was charged with misdemeanor counts of driving under the influence of alcohol and driving with a BAC of 0.08% or more, in violation of California Vehicle Code §23152(a) and §23152(b), respectively.

In the realm of playground safety litigation, the involvement of a Playground Safety Expert Witness can be pivotal in determining the outcome of a case. A notable example is the case of K.M. v. Deer Park Union Free School District, 2019 N.Y. Misc. LEXIS 695 (Feb. 19, 2019), which underscores the critical role such experts play in legal proceedings concerning playground injuries.

Background of the Case

The incident occurred during a lunch recess when K.M., a minor student at John Quincy Adams Elementary School, was playing on a piece of playground equipment known as the “Spider” climbing apparatus. This structure consisted of horizontal bars designed for climbing and play. K.M. climbed atop the horizontal bars, sat while holding onto the bars on each side, and hung her feet through an opening. She then attempted to jump down through the open space where her feet had been dangling, but in the process, she hit her teeth on one of the bars and landed on the ground, sustaining injuries.

In September 2022, Pamela Morrison, a 74-year-old Arizona resident, visited Universal Studios Hollywood’s Wizarding World of Harry Potter with her grandson. As part of their visit, they decided to experience the popular attraction “Harry Potter and the Forbidden Journey.” While attempting to board the ride, Morrison encountered difficulty with the safety harness, which failed to secure properly. Ride operators informed her that she would not be able to ride and directed her to exit the moving walkway.

As she attempted to step from the moving walkway onto solid ground, Morrison lost her footing and fell. The incident resulted in severe injuries, including a fracture in her lower back and a significant muscle tear around her hip. The aftermath of the fall required extensive medical care and left Morrison with long-term mobility challenges and chronic pain.

Following the incident, Morrison filed a lawsuit against Universal Studios Hollywood, alleging negligence in the operation of the attraction and the unsafe design of its exit system. Her legal team argued that Universal failed to ensure her safety when the harness malfunctioned and that the moving walkway should have been stopped to allow her to exit safely. Furthermore, they contended that park employees were more concerned with keeping the ride on schedule—operating at an estimated 1,800 riders per hour—than they were with attending to a vulnerable guest.

In the case of Price v. Carnival Cruise Lines, No. 20-cv-20621-BLOOM/Louis (S.D. Fla. 2020), the United States District Court for the Southern District of Florida addressed the admissibility of expert testimony in a maritime personal injury lawsuit. The plaintiff retained Dr. John H. Shim as an expert witness to testify regarding the injuries sustained during a cruise. The court’s analysis provides insight into the role and evaluation of a Cruise Lines Expert Witness in such cases.

Case Background

The plaintiff initiated a maritime personal injury action against Carnival Cruise Lines, alleging injuries suffered on February 28, 2019, while aboard the M/V Carnival Valor. To support her claims, the plaintiff retained Dr. John H. Shim, an orthopedic surgeon, as an expert witness. Dr. Shim was expected to testify about the plaintiff’s injuries, his review of her medical records, diagnostic tests, findings, diagnosis, prognosis, the need for future medical treatment, and the associated costs. He was also anticipated to opine that the plaintiff sustained permanent injury as a result of the incident and that the medical services rendered were reasonable, necessary, and related to the incident.

In the case of Food & Water Watch, Inc. et al. v. U.S. Environmental Protection Agency, No. 3:17-cv-02162-EMC (N.D. Cal. 2024), the United States District Court for the Northern District of California addressed a significant environmental health dispute concerning the fluoridation of public drinking water. The plaintiffs alleged that the addition of fluoride to drinking water posed an unreasonable risk of neurotoxic harm, particularly to infants and young children. Expert testimony played a pivotal role in this case, with both parties presenting scientific evidence to support their positions.

Case Background

In November 2016, a coalition of organizations and individuals, including Food & Water Watch and the Fluoride Action Network, petitioned the Environmental Protection Agency (EPA) under Section 21 of the Toxic Substances Control Act (TSCA) to prohibit the addition of fluoridation chemicals to drinking water. The petitioners argued that fluoride exposure is linked to neurodevelopmental issues, such as reduced IQ in children. The EPA denied the petition in February 2017, leading the plaintiffs to seek judicial review of the denial.

In the case of Burke v. Glanz, No. 4:11-CV-00720-JED-PJC (N.D. Okla. 2017), the United States District Court for the Northern District of Oklahoma addressed a wrongful death lawsuit concerning the 2011 death of Elliott Williams in the Tulsa County Jail. The testimony of expert witnesses was pivotal in establishing the circumstances leading to Williams’s death and determining liability.

Case Background

Elliott Williams, a 37-year-old Army veteran, was arrested on October 21, 2011, for misdemeanor obstruction of a police officer and subsequently detained at the Tulsa County Jail. During his incarceration, Williams suffered a severe injury resulting in paralysis. Despite his evident medical distress, jail staff neglected to provide necessary medical care, leading to his death on October 27, 2011. The medical examiner determined that Williams died from complications of vertebrospinal injuries due to blunt force trauma, compounded by starvation and dehydration.