Expert Witness Profiler

Tag: Toxicology

  • Toxicology Expert’s Testimony on Hair Follicle Testing Admitted

    Toxicology Expert’s Testimony on Hair Follicle Testing Admitted

    Plaintiff Darius Danzy filed this suit against CSX Transportation Inc. in this action under Title VII of the Civil Rights Act of 1964, as amended (“Title VII”) alleging “unlawful employment practices on the basis of race.”

    Plaintiff’s claims arise out of a pre-employment drug-screening that Defendant administered to Plaintiff through third party drug testing companies, Psychemedics Corporation (“Psychemedics”) and Omega Laboratories, Inc. (“Omega”).

    According to the Plaintiff, Defendant discriminated against him because of his race as a “Black-African American” by subjecting him to narcotic testing that disparately impacts the “class of Black African Americans” due to the allegedly unreliable and inaccurate method of hair follicle testing used by Defendant through Psychemedics in its pre-employment drug screening.

    The Defendant retained Dr. R.H. Barry Sample to review the testing performed by Psychemedics of Plaintiff’s underarm hair specimen.

    Plaintiff sought to exclude the testimony of Sample and the hair test results provided by Psychemedics pursuant to Rules 702 and 104(a) of the Federal
    Rules of Evidence.

    Toxicology Expert Witness

    Dr. R.H. Barry Sample is a forensic toxicologist with a Ph.D. in the field of Pharmacology from Indiana University and has worked in the field of forensic toxicology for over thirty-five years.

    For over twenty years Sample worked as the Director of Science and Technology for Quest Diagnostics, “one of the largest forensic workforce (workplace) drug testing laboratory providers in the United States.” Sample served two separate four-year terms as a member of the Substance Abuse and Mental Health Services Administration (“SAMHSA”) Drug Testing Advisory Board (“DTAB”) and advised on the SAMHSA drug testing activities and laboratory certification program.

    Sample continues to serve as a commissioner and laboratory inspector for the College of American Pathologists (“CAP”) in its Forensic Drug Testing (“FDT”) accreditation program (“CAP-FDT”). Sample has been licensed or certified by various states as a laboratory director in the area of forensic workforce drug testing.

    Want to know more about the challenges R.H. Barry Sample has faced? Get the full details with our Challenge Study report.

    Discussion by the Court

    Sample opined that Psychemedics’ test results are accurate and scientifically reliable and that Omega’s test results confirmed the accuracy of Psychemedics’ test results.

    Plaintiff primarily brought a relevance-based argument that hair follicle testing itself is legally improper as this methodology is not included in the regulations of SAMHSA.

    A. Relevance

    According to the Plaintiff, SAMHSA in its 2020 Proposed Hair Guidelines explicitly excludes Benzoylecgonine (“BZE”) as a reliable confirmatory marker due to its low concentrations in hair and the absence of validated thresholds.

    Plaintiff contended that “Congress explicitly assigned SAMHSA the exclusive
    role to regulate drug testing in Federally regulated industries through the Omnibus Transportation Employee Testing Act.”

    Sample served two (2), four-year terms as a Member of the SAMHSA Drug Testing Advisory Board which advises the Assistant Secretary of SAMHSA, on the review of the direction, scope, balance, and emphasis of the SAMHSA drug testing activities and the drug testing laboratory certification program.

    The Court found that his experience provided him with unique insights into the scope and requirements of SAMHSA drug testing. Sample acknowledges that “only urine drug testing is possible under DOT rules” and that the hair sample test that Defendant undertook “is not covered by the requirements of the DOT, Federal Railroad Administration (‘FRA’), or [SAMHSA].”

    Sample noted that “neither the DOT nor SAMHSA (which the DOT relies on for technical guidelines) have published final requirements for hair testing.”

    The Omnibus Transportation Employee Testing Act of 1991 directed the Secretary of Transportation to develop regulations for the testing of employees for drugs and alcohol in four sectors of the transportation industry, including railroads.

    Notably while the statute requires that “laboratories and testing procedures for controlled substances, incorporate the Department of Health and Human Services scientific and technical guidelines,” they do not prohibit a private employer in the railroad industry from conducting additional drug testing procedures beyond those prescribed by the DOT.

    In sum, the Court held that Sample’s opinions are outside the common experience of lay persons and, therefore, explains the unique process of hair follicle testing for drug usage.

    B. Reliability

    Plaintiff’s primary objections to Sample’s report focus on its reliability. Specifically, Plaintiff contended that there is a lack of reliable, scientific evidence surrounding the use of BZE as a biomarker in hair testing.

    However, Sample provided a thorough summary of the documents he reviewed in support of his report, as well as the work he undertook in forming his opinions.

    Sample noted that both of the laboratories that tested Plaintiff’s hair follicle “are accredited under the CAP-FDT Accreditation Program for hair testing as well under the New York State Department of Health – Clinical Laboratory Evaluation Program for hair testing” and that they both hold “ISO/IEC 17025 accreditation.”

    Plaintiff’s critique did not make detailed arguments finding fault with specific elements of Sample’s methodology or approach. Rather, Plaintiff appeared to argue that because other sources, including the federal government, have allegedly come to different conclusions, Sample ’s methodologies must be flawed. The Court, however, held that Plaintiff’s objections relate to the weight to be given to Sample’s opinions, not their admissibility.

    The Court found that the Defendant has demonstrated by a preponderance of the evidence that Sample and his report satisfied the standard for expert
    scientific testimony.

    Held

    The Court denied the Plaintiff’s motion to exclude the testimony of Dr. R.H. Barry Sample.

    Key Takeaway:

    The Court’s reliability analysis focuses on the “‘principles and methodology’ employed by the expert, not on the conclusions reached.”

    In addition to his own experience, Sample explained that his opinion is based on “peer-reviewed scientific literature regarding forensic workforce drug
    testing.” Sample also cited peer-reviewed sources in support of his
    conclusions.

    Case Details:

    Case Caption: Danzy V. CSX Transportation, Inc.
    Docket Number: 5:23cv621
    Court Name: United States District Court, North Carolina Eastern
    Order Date: September 19, 2025
  • Toxicology Expert Witness’ Testimony Related to Cannabis and Workplace Deficiencies Admitted

    Toxicology Expert Witness’ Testimony Related to Cannabis and Workplace Deficiencies Admitted

    On February 22, 2021, Justin Demary was working for Freedom Trucks of America, LLC (“Freedom Trucks”). He was asked to wash out a tank truck owned by Freedom Trucks. It appears that there is a dispute as to whether Justin was asked to wash the tank truck, or he entered the tank truck of his own volition, or at the behest of his friend and co-worker, Dustin Wynn. Justin and Wynn were unaware that the tank truck had been purged with nitrogen at the Vopak Terminal Deer Park facility (“Vopak Terminal”) because no warning tag was placed on the tanker by Vopak North America, Inc. (“Vopak”). Again, this is a disputed fact; a Vopak employee has testified that he did place a warning tag on the tank truck.

    Vopak operates a storage facility at which Freedom Truck had a liquid chemical cargo removed from the tanker about a month before Justin’s accident. The tanker was then transported back to Freedom Truck’s yard on or about January 27, or January 28, 2021, where it sat dormant until the date of the accident.

    Justin entered the tanker to perform the task but could not breath. He passed out and died of asphyxiation. Justin’s parents and only heirs, Daniel and Tammy Demary, have filed this wrongful death action against several Defendants for the death of their son.

    Motion to Exclude

    Vopak Terminal had hired Dr. Pablo Sanchez-Soria as an expert toxicologis/pharmacologist who is anticipated to testify that the level of cannabinoids and THC metabolites in Justin’s blood far exceeded the threshold for impairment. As such, Justin’s alleged impairment contributed to his decision to enter the tanker and his ultimate death.

    Plaintiffs requested that the Court exclude Soria’s testimony related to cannabis and workplace deficiencies at Freedom Trucks pursuant to Rule 702 of the Federal Rules of Civil Procedure and Daubert.

    Toxicology Expert Witness

    Pablo Sanchez-Soria is a Senior Toxicologist and Director of Health Sciences at CTEH® specializing in risk and exposure assessment, toxicity evaluations, emergency response toxicology, and in evaluating relationships between chemical exposure and disease causation. He has a double major in microbiology and nutritional sciences and a PhD in pharmacology and toxicology. He has been involved in the practice of toxicology and industrial hygiene and has specialized in quantitative exposure reconstruction of occupational and environmental hazards.

     Soria has served as a consulting toxicologist and industrial hygienist, and has developed plans to protect workers and communities from chemical exposure. Additionally, as a practicing toxicologist, he has evaluated the impairment and risk-perception impacts associated with the use of alcohol, and recreational, illicit and prescription drugs. He routinely conducts disease causation analysis by evaluating the scientific evidence relating chemical exposures to human diseases according to the methodology of toxicological causation analysis. Soria’s curriculum vitae lists numerous publications and presentations related to the study of toxicology, several of which relate to the effects of toxicants on the human body.

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

     

    Discussion by the Court

    Vopak’s defense in this case is that Justin’s death was caused by his own negligence and by the negligence of his employer, Freedom Trucks. Soria opines as to the following in his report:

    1. The use of cannabis is associated with impaired cognitive function and physiological response, including impairments in decision-making, risk-taking, balance, coordination, reaction time, spatial perception which may increase the risk of being involved in an accident due to impaired cognitive and motor skills. These impairments are associated with blood concentrations of cannabis and its metabolites in a dose-dependent manner.

    2. The presence and concentration of cannabis and its metabolites, 11-OH-THC in Demary’s blood sample results are useful indicators that he would have recently consumed (inhaled or ingested) cannabis.

    3. Demary’s employer did not properly establish industrial hygiene measures to control workplace hazards, highlighting a disregard for established safety protocols and the well-being of their employees.

    Qualifications

    Plaintiffs argued that Vopak cannot meet its burden to show that Soria has the requisite qualifications to opine on medical toxicology and the alleged impairment due to cannabis use. Plaintiffs pointed out that Soria’s education was focused on pharmacology and toxicology, but he is not a medical doctor, nor has he disclosed any specific training on medical toxicology or the effects of cannabis on the human body and any alleged impairment. It was noted that Soria has not authored any publications nor made any presentations regarding cannabis and its effect.

    Soria reviewed the NMS Labs toxicology report that established that Justin’s blood levels of THC were reported to be 9.9 ng/mL. Soria concluded that it was more likely than not that Justin was suffering from motor and cognitive impairments that may have contributed to his demise as a result of poor decision making. His report seeks to provide insight into effects that the specific amount of THC discovered in Justin’s bloodstream would likely have had on his body and mind while conscious, but makes no effort to challenge medical opinions or the cause of Justin’s death. The Court found that Soria is qualified to testify as an expert as to the effect of THC on the mind and body.

     Relevancy

    Defendants argued that Soria’s testimony is relevant because the evidence and facts—lab results, autopsy reports, testimony relating to marijuana use and chemical inhalation, etc.—involve complicated scientific issues, which, if brought before a jury without further explanation, are highly likely to leave the trier of fact confused and unable to reach a well-informed conclusion. Hence, Soria’s testimony is necessary to assist a jury in understanding that based upon science, the level of cannabinoids in a human system can make one impaired and have poor judgment. Defendants noted that precedential authority almost unanimously vouches for the admission of a toxicologist’s testimony to assist the trier of fact in understanding complex topics rooted in science, especially toxicology. Defendants cite to numerous cases that have held that evidence of impairment is relevant, admissible, and important to the issue of contributory negligence.

    Additionally, Defendants cite to numerous cases in which toxicologists are routinely allowed to testify about failed drug tests and the impairment of the drug-user. 

    Defendants also noted that Justin’s supervisor, Mark Francis, testified that Justin was never directed to enter the tank, and that 90 percent of tank cleanings are never done on the interior. It appeared that Defendant is attempting to show that Justin entered the tank of his own volition, entering the tank was a departure from protocol, and collectively revealed a pattern of erratic and irrational decision making by Justin. The Court found that Soria’s opinion as to Justin’s levels of THC and possible impairment is relevant.

    Reliability

    Plaintiff argued that Soria’s opinions as to Justin’s cannabis use and timing are inadmissible because they are based on unreliable and incomplete information.

    Plaintiffs complained that Soria does not reference Justin’s height, weight, or body habitus to discuss the effects that could have occurred in Justin due to cannabis ingestion, nor can he suggest the timing as to when Justin ingested cannabis. Plaintiffs fault Soria for the lack of evidence to establish the timing and as such, argued that Justin’s cannabis impairment cannot be verified. It was also noted that cannabis is not listed on the death certificate as a cause of death in the autopsy.

    Defendants remarked that the countless cited scientific methods can be applied to the facts of this case, and Soria details how the science of toxicology can tie together various case materials to offer a viable explanation for Justin’s behavior at the time of the incident.

    The Court found that Soria’s opinions are supported by peer-reviewed scientific studies and facts such as the lab results and deposition testimony. As such, a rigorous cross-examination would be the proper vehicle to challenge Plaintiffs’ objections as opposed to excluding the expert’s testimony.

    Held

    The Court denied the Plaintiffs’ motion to exclude the opinions of Defendant’s expert witness Pablo Sanchez Soria.

    Key Takeaway:

    As a practicing toxicologist, Soria has evaluated the impairment and risk-perception impacts associated with the use of alcohol, and recreational, illicit and prescription drugs. Considering that, the Court held that Soria’s opinion as to Justin’s levels of THC and possible impairment is relevant. His report seeks to provide insight into effects that the specific amount of THC discovered in Justin’s bloodstream would likely have had on his body and mind while conscious, but makes no effort to challenge medical opinions or the cause of Justin’s death. 

    Case Details:

    Case Caption: Demary V. Freedom Trucks of America LLC
    Docket Number: 2:22cv792
    Court: United States District Court, Louisiana Western
    Order Date: December 6, 2024
  • Toxicology Expert Witness’ Testimony Regarding the Plaintiff’s Blood Alcohol Content Admitted

    Toxicology Expert Witness’ Testimony Regarding the Plaintiff’s Blood Alcohol Content Admitted

    Plaintiff Sandra Corbin filed a civil rights action against the Defendants Bill Prummell, Jr., as sheriff of the Charlotte County, David Gensimore, and Aaron Williams as a result of Corbin sustaining a fractured leg, and a litany of related and subsequent damages due to excessive force employed by Williams.

    On November 29, 2019, at around 9:45 PM, Plaintiffs, John Corbin and Sandra Corbin were stopped by Charlote County Deputies Michael Davidson and Aaron Williams. Plaintiffs were stopped upon leaving a restaurant/bar where both Mr. Corbin and Mrs. Corbin consumed a couple of beers.

    During the traffic stop of Plaintiffs, Mr. Corbin was removed from the vehicle by Deputy Davidson to perform a field sobriety test (FST), while Mrs. Corbin remained in the vehicle. Mrs. Corbin attempted to go around Deputy Williams to observe what was happening with Mr. Corbin; and at that moment Deputy Williams deployed a “leg sweep” or “leg whip” with such force it took Mrs. Corbin to the ground; and fractured her leg.

    Corbin filed a motion to exclude the testimony of Defendants’ proposed expert, Teri L. Stockham, a forensic toxicologist who opined that Sandra Corbin was intoxicated such that her normal faculties were impaired at the time of this incident. This opinion is based on scientific evidence of the hospital serum ethanol result of 206 mg/dL almost two hours after the incident.

    Toxicology Expert Witness

    Teri Stockham holds three degrees: A Bachelor of Science in chemistry, a Master of Science in forensic science and forensic toxicology, and a Doctor of Philosophy in pharmacology and toxicology. She has thirty-five years of toxicology experience, including a stint as Chief Toxicologist at Broward County Medical Examiner’s office.

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

    Discussion by the Court

    Qualifications

    The Corbins argued that Stockham was not qualified to testify on Sandra Corbin’s state of mind, behavior, etc., that her opinion was not based on reliable scientific or technical testing, and that the testimony will not assist the trier of fact.

    Plaintiffs argued that Stockham, as a toxicologist, is not qualified to opine on how Sandra Corbin comported herself during the night in question since Stockham “never met with Sandra Corbin, nor discussed the events of November 29, 2019.”

    The Court held that Stockham is not testifying that she personally knows Corbin behaved a certain way during the night in question. She is offering testimony regarding Corbin’s blood alcohol content (BAC) and the “signs and symptoms” she would “expect” with that BAC.

    Hence, the Court held that Stockham is qualified as an expert to interpret BAC “not because of her familiarity with Sandra Corbin, but because
    of her familiarity with the analysis she was tasked with performing.”

    Reliability

    Plaintiffs argued that Stockham’s testimony was not reliable for many reasons, including because it relied not on statistical data but on Sandra Corbin’s blood alcohol level taken two hours after the event and did not consider pertinent deposition testimony or Sandra Corbin’s alcohol tolerance level.

    Stockham’s opinion is based “on scientific evidence of the hospital serum ethanol result of 206 mg/dL” which she converted to BAC. The Court held her opinion is reliable because it is generally accepted that alcohol content levels give reliable estimates of a person’s intoxication, and “[a]nalysis of blood samples gives the most accurate results.”

    Assistance to the trier of fact

    The third requirement asks “whether that reasoning or methodology properly can be applied to the facts in issue.”

    Plaintiffs argued that “an opinion or determination of intoxication” is unhelpful here as Florida’s driving under the influence statute is irrelevant and “there is no requisite or comparable BAC level under” Florida’s disorderly intoxication statute.

    The Court held that Stockham’s opinions regarding Corbin’s BAC and the effects expected of a person with that level of BAC “are helpful for the factfinder because, although the general effects of alcohol consumption are commonly known, the methodology for determining an individual’s BAC and an opinion on the associated physiological manifestations of a specific BAC level are beyond the understanding and experience of the average lay citizen and goes to the ultimate finding” of whether Corbin was intoxicated.

    Held

    The Court denied the Plaintiffs’ motion to exclude the testimony of Teri L. Stockham.

    Key Takeaways:

    None of Plaintiffs’ arguments to exclude Stockham’s testimony are persuasive. Stockham is qualified, her outlined opinion above is reliable, helpful, relevant, and its probative value does not outweigh the danger of unfair prejudice, confusion of the issues, or misleading of the jury.

    • Even if accepted as true that, for example, certain deposition testimony was omitted, misstated, or contradicted and that pertinent information such as Corbin’s age, fatigue, or food consumption was overlooked, any such shortcomings would go to the weight of the evidence, not to admissibility.
    • Plaintiffs’ argument misconstrued Stockham’s offered testimony and applied a higher bar for the qualification of an expert than precedent required.

    Case Details:

    Case Caption: Corbin Et Al V. Prummell, Jr. Et Al
    Docket Number: 2:22cv394
    Court: United States District Court, Florida Middle
    Order Date: July 25, 2024