Neurotoxicology Expert Witnesses

Rudolph Johnson, PhD, is a Chemical Toxicologist with over 20 years of experience in analytical chemistry and toxicological investigations. Dr. Johnson's past experience includes directing the (1) clinical toxicology network, LRN-C, at the Centers for Disease Control and Prevention and (2) the Military Exposures Research Program at the US Department of Veterans Affairs. Currently, he serves as the Director of the Wisconsin State Laboratory of Hygiene and has a faculty appointment at the University of Wisconsin-Madison School of Medicine and Public Health, Department of Pathology.

Dr. Johnson focuses on two specialty areas:

(A) Toxicology: He offers causation opinions connecting dose, analytical detection, and biomarker findings to determine whether and to what extent an individual was exposed to a chemical or toxin.  The chemical or toxin may be inhaled, ingested or injected. This includes drug and alcohol testing.

(B) Laboratory Testing: He critiques or defends laboratory testing methodology, chain-of-custody, and quality assurance practices. He is an expert at evaluating conflicting testing data between two labs.

Litigation Support - Dr. Johnson works with plaintiff and defense litigation attorneys on toxic tort, product liability, and environmental and occupational exposure cases requiring causation analysis. He supports criminal defense and plaintiffs reviewing drug exposures (opioids, fentanyl analogs, polypharmacy) and alcohol testing. This includes chain-of-custody, and quality practices. Conflicting or inconsistent laboratory data, especially between multiple laboratories, is a specialty area of Dr. Johnson because he previously directed multiple clinical toxicology labs.

Dr. Johnson detects, quantifies, and interprets chemical and toxic exposure in human clinical samples. He is skilled in translating investigative information into causation opinions, connecting dose, biomarker significance, and clinical outcome—for poisoning, occupational, environmental, and mass-casualty toxicology cases.

Areas of Expertise:

RedSpire, LLC delivers end-to-end Exposure Science and Occupational Epidemiology services to support data-driven decision making. RedSpire's expert analysis is fast, deep, and cost-effective and their technology amplifies their expertise. RedSpire's scientists turn strategy into actionable outcomes.

Litigation Support - Ideal clients are attorneys or firms involved in toxic tort litigation, particularly those with occupational exposures, who are interested in a technology-forward approach to streamline the expert witness work. RedSpire is interested in clients who want to transform how the industry integrates science into legal cases, through more systemic applications of technology that can bring the science of a case to the forefront in ways that reduce the reliance on expensive and time-consuming expert witness work.

Dr. Kristen Good is an Epidemiologist and Certified Industrial Hygienist (CIH) with over 15 years of scientific background and experience in risk assessment, toxicology, exposure assessment, and environmental sciences, across academia/research, private industry, and government sectors. She is passionate about identifying data-driven, scientifically-supported solutions to complex problems - and communicating those solutions to stakeholders and the public. She has a Ph.D. in Environmental Health with an epidemiology concentration from Colorado State University, a Master's degree in Environmental Management, toxicology focus, from Duke University, and a B.S. in Biology from Boston College.

Dr. Good has served as the leading technical authority in occupational health and indoor air quality at the Colorado Department of Public Health and Environment (CDPHE) since 2020. She manages the state’s indoor air quality improvement programs and occupational health surveillance and response initiatives. She regularly advises partners, workplace managers, and the general public on health and safety regulations and best practices, PPE and administrative controls to reduce exposures/safety risks, employer liabilities related to occupational health and safety, and post-incident response related to a variety of occupational health and safety concerns and scenarios.

From 2020-2022, Dr. Good led the Industry Response Team of the state’s COVID-19 pandemic response. She was responsible for advising on workplace outbreak prevention, investigation, and response for hundreds of workplace outbreaks, and employer responsibility across a wide variety of industry sectors. She also worked with the Governor’s Office and other state agencies on COVID-19 guidance and policy development.

Areas of Expertise:

Dr. Nicholas Good, Co-Founder and Exposure Science Lead, is an Aerosol Scientist with over 20 years of experience in Scientific Instrument Development, Evaluation, and Deployment. He has worked across academia, research, and private industry in aerosol exposure sciences, indoor air quality, and environmental health. Dr. Good focuses on bridging emerging technology—both hardware and software—from the research laboratory into solutions for practical real-world problems. He holds a Ph.D. in Atmospheric Science from Manchester University and a B.S in Physics from The University of Manchester.

Dr. Good provides consulting services supporting clients' needs in occupational health and safety, exposure assessment, and environmental health issues—with particular focus on asbestos and benzene exposure reconstructions. In addition to his role with RedSpire, Dr. Good owns Good Science LLC (2019-present), which provides specialized environmental consulting services primarily for legal clients, and co-founded CloudSci LLC (2023) a company commercializing airborne particle measurement technologies for research and related markets.

Since 2017, Dr. Good has served as Research Scientist at Colorado State University (first in the Department of Environmental & Radiological Health Sciences, and now in the Department of Civil and Environmental Engineering), leading research on air quality and human health with emphasis on indoor air quality, building performance, bioaerosols, and novel health effects of air pollution.

Areas of Expertise:

Dr. Gavin McMeeking, Chief Executive Officer & Co-Founder, is an Aerosol Scientist with over 20 years of experience in Scientific Instrument Development, Evaluation, and Deployment. He has worked across academia, research, and private industry in atmospheric chemistry, cloud physics, aerosol measurements, and environmental health. Dr. McMeeking focuses on bridging emerging technology—both hardware and software—from the research laboratory into solutions to practical real-world problems. He holds a Ph.D. and M.S. in Atmospheric Science from Colorado State University and a B.A. in Earth and Planetary Science from UC Berkeley.

Dr. McMeeking leads the company's strategic direction and client services. He co-founded CloudSci LLC (2023), which commercializes airborne particle measurement technologies for research and related markets. Previously, he held leadership roles at Handix Scientific LLC, first as a Senior/Principal Scientist (2015-1010) and then as VP of Research & Development (2020-2022), and worked as a Scientist/Sales Specialist at Droplet Measurement Technologies (2012-2015). He has advised governmental organizations including the Department of Energy, National Science Foundation, and NASA on topics ranging from instrument development, atmospheric measurement techniques, black carbon aerosol impacts, wildfire emission characterization, and technology translation.

Areas of Expertise:

View RedSpire, LLC's Consulting Profile.

Sara J. Schreiber, PhD, D-ABFT-FT, is a worldwide leader and highly accomplished Forensic Toxicologist, Educator, and Consultant whose work has earned recognition at both the national and international levels through leadership, teaching, professional service, and participation in major forensic pursuits.

Dr. Schreiber has more than two decades of experience in forensic science, including over 25 years in Toxicology and Controlled Substance Analysis, and has served in senior laboratory, technical director, academic, and expert roles in governmental forensic institutions.

Litigation Support - Dr. Schreiber provides comprehensive technical review and expert analysis in complex criminal and civil matters where alcohol, drugs, and poisons are at issue. Her work bridges the gap between advanced toxicological data and the courtroom by critically evaluating laboratory methods, case files, bench notes, instrumental data, and reports to determine whether testing, interpretation, and quality practices meet accepted forensic and accreditation standards, including ISO/IEC 17025, American Board of Forensic Toxicology (ABFT), and relevant professional guidelines. 

Dr. Schreiber draws on her experience as a diplomate of the American Board of Forensic Toxicology and her leadership roles in organizations such as MAFS, SOFT, NAME, OSAC, and TIAFT. When requested, she provides clear, accessible expert testimony, affidavits, and consultation to attorneys, investigators, and courts, translating complex toxicological and medicolegal issues into opinions that can be understood and evaluated by judges and juries.

Areas of Expertise: 

Background Experience - Dr. Schreiber’s national notoriety is reflected in her repeated invitations to lecture, train, and present on forensic toxicology, opioid deaths, toxicology trends, medicolegal death investigation, expert testimony, and related forensic topics for professional associations, public defenders, prosecutors, medical and university audiences, public health groups, and scientific meetings across multiple states throughout the US. Her work has also contributed to public-health and death-investigation initiatives through overdose fatality review teams, national overdose fatality review consulting, Department of Justice (DOJ), National Institute of Justice (NIJ), and the RTI Center for Forensic Sciences technology Working Group participation, and overdose-related strategy teams.

Consultants. Experts. Innovators.™

Operating from more than 110+ offices around the globe, we provide services to corporations, insurance companies, law firms, and government agencies.

Rimkus experts specialize in forensic consulting and construction dispute resolution in the hospitality, retail, and restaurant; industrial; marine; oil and gas; power and renewable energy; transportation; and pharmaceuticals industries.

Rimkus experts solve complex challenges wherever in the world they occur. We are dedicated to serving our clients so they can achieve timely resolution of accidents, claims, and legal disputes.

Our highly diversified, global team of engineers, scientists, architects, and technical specialists systematically evaluates all available evidence, applies scientific principles, specialized knowledge and, when appropriate, utilizes the latest analytical technologies to arrive at scientifically sound opinions and solutions for our clients.

Rimkus Global Services Overview

OUR FORENSIC SERVICES EXPERTISE

View our full suite of Forensic Expert Services

GLOBAL OFFICES

Rimkus operates from 110+ offices worldwide, with headquarters in the following cities.

View a full list of Rimkus Office Locations.

View Rimkus Quantum and Delay Expert Services Profile.
View Rimkus Life Sciences Expert Services Profile.

Dr. David H. Schaffer, MD, MRO, is Harvard-trained and dual-boarded in Medical Toxicology and Emergency Medicine, serving as the Chief of the Division of Medical Toxicology at Prisma Health–Upstate and faculty at the University of South Carolina School of Medicine in Greenville, SC. He is also a certified Medical Review Officer (MRO, MROCC).

Dr. Schaffer is regularly consulted for his expertise. Overall case retention is approximately 50/50 for plaintiff vs defendant. His services include medical record review, thorough reporting, deposition, and trial testimony as needed. Please feel free to call (828) 260-3742 or email david@schaffertox.com to walk through your case. No charge/bill time for this. Case highlights or referral available upon request.

Areas of Expertise:

Dr. Schaffer has published extensively in the fields of Medical Toxicology and Emergency Medicine. Outside of clinical practice and the occasional courtroom appearance, he has also consulted for major organizations—including SpaceX, Butterfly Network, and governmental entities—on a variety of clinical matters. Dr. Schaffer earned his medical degree from the University of North Carolina School of Medicine, completed his residency at Harvard, where he served as a Clinical Fellow at Harvard Medical School, and subsequently trained in Medical Toxicology at the University of Virginia.

Credential Highlights:

• Residency Training at Harvard and Massachusetts General/Brigham & Women's Hospitals
• Held appointment at Harvard Medical School as a Clinical Fellow
• Fellowship training at the University of Virginia
• Division Chief of Medical Toxicology at Prisma Health - Upstate, the only Medical Toxicology practice in the State of SC
• Faculty at USC School of Medicine in Greenville, SC and at Clemson University
• Attending Toxicologist for the Palmetto Poison Center in Columbia, SC
• Certified Medical Review Officer (DOT/HHS)
• Board-certified in both Emergency Medicine and Medical Toxicology