Aiding the Investigation: The Role of Toxicology in Litigation and Claims

Authored by Amanda M. Kogelschatz, M.S., D-ABFT-FT, Senior Toxicologist
Published June 30, 2026

A version of this article originally appeared in the May/June 2026 issue of CLM Magazine (pages 10-11).

Article Overview

The article explains how forensic toxicology findings can help shape an effective case approach. It offers clarity on questions of impairment, the type of drug or substance involved, and the effects it can have on the body.

Drawing on real-world scenarios, Rimkus Senior Toxicologist, Amanda M. Kogelschatz, M.S., D-ABFT-FT, walks through how a forensic toxicologist helps the case. This includes reconstructing drinking and exposure timelines, interpreting the differences between blood and urine results, and identifying the records and evidence most useful for a toxicology review.

Amanda shares her experience below as a guide for attorneys, insurers, claims professionals, and risk managers handling matters involving alcohol, drugs, or chemical exposure.

Making Sense of Alcohol and Drug Toxicology Evidence

Understanding how toxicological findings play a role in your case can assist in having an effective case approach. Forensic toxicologist experts can offer insights into the relevance of the toxicological findings to the question(s) at hand, such as impairment, the type of drug found, and the type of effect it can have on the body. This type of evaluation may pertain to car accidents, slips, falls, workplace accidents, sales related to alcohol or drugs, and wrongful death investigations.

Alcohol and Drug Pathways and Potential Effects

Every drug has a unique metabolic pathway in the body. There are several factors to consider when evaluating what the possible effects may be on a person such as the drug itself, dose, route of administration (how the drug is ingested), a person’s physiological parameters (age, weight, height, sex), and frequency of use.

For example, alcohol, a central nervous system (CNS) depressant, has a straightforward metabolic pathway in the body. Alcohol is absorbed from the gut, distributed to the bloodstream, primarily metabolized in the liver, and then eliminated from the body through breath, sweat, or urine. Alcohol has a well-known dose-response relationship.

Drugs have a more complex metabolic pathway. Most drugs further break down into metabolites which may be psychoactive producing an effect on the body. Some drugs, such as marijuana, may linger in the body longer as they are more partial to the fat in the body. Often when drugs are taken in combination, they may produce additional impairments and can result in a more complex evaluation.

Below are three case scenarios involving alcohol and drugs where a Forensic Toxicologist may provide expertise.

Case Scenario #1: Motor Vehicle Accident/Dram Shop

A 25-year-old male and a pedestrian were involved in a motor vehicle accident. The driver had just visited a bar with some friends. Toxicology results from the driver’s blood found a blood alcohol concentration (BAC) of 0.06 g/dL and was positive for marijuana-related compounds.

During investigation, the driver admitted that he had two beers and smokes marijuana frequently. The last time he smoked was right before he entered the car.

Question #1: Was the driver overserved?

If the information is available, a toxicologist may be able to reconstruct the drinking timeline to determine the BAC at various timepoints of consumption and possibly at the point of service. To perform these types of analyses, the individual’s physiological parameters of age, sex, height, weight, and any measured BAC values from a blood draw would be utilized.

If appropriate, the following calculations may be performed:

• Retrograde: estimates the driver’s BAC at a timepoint prior to the blood draw, including, the point of service and at the time of accident.
• Anterograde: to determine what the BAC would be at a timepoint after consumption when the drinking history is known (amount, type, brand, consumption times). This type of calculation can be helpful to show if the number of drinks purchased could have produced the measured BAC.
• Quantitation: can determine how many drinks would be needed to obtain the measured BAC value.

All this information may be used to determine if the driver may have been visibly intoxicated at the time of service.

Question #2: Was the driver impaired at the time of the accident?

There are some combinations of drugs with alcohol that may produce additional adverse effects or impairments. It is well studied and known that alcohol and marijuana taken together can produce additional decrements when driving. Knowing when the driver last used marijuana would be helpful in assessing potential effects and decrements specific to driving.

Case Scenario #2: Accident/Fall

Early in the morning, an individual falls down a few steps and breaks their ankle. At the hospital, an ethanol test was performed with a result of 220 mg/dL.

Question: Did alcohol contribute to the fall?

In this scenario, the measured alcohol was from a hospital blood draw. Most hospitals measure in serum/plasma and are not in whole blood. Hospital alcohol values are often reported in units of mg/dL. A value of 220 mg/dL is equivalent to 0.220 g/dL. Since serum/plasma has a higher water content, an adjustment needs to be made to the measured hospital result which will lower the reported number to convert to a whole blood alcohol concentration. Like the earlier example, BAC calculations may be performed based on the information available to give a better understanding of the drinking history and potential impairment prior to the fall.

Understanding the timeline of events leading up to the fall including the drinking history may be helpful in the analysis.

Case Scenario #3: Urine Drug Testing

A workplace accident has occurred; the employee was drug tested via a urine sample. Their urine drug test was positive for marijuana-related compounds. The employee testified he took an edible before bed the previous night.

Question: Was the driver impaired at the time of the accident?

There is a difference in the interpretation of urine and blood results. Once a drug reaches the bloodstream and is circulating in the body, it can interact with the systems in the body producing an effect. Urine results reflect what the body has already processed and does not reflect what is in the bloodstream. Drugs can also linger in the urine longer than they will in the blood.

Any measured values of marijuana metabolites in urine do not reflect what the blood value is and cannot be used to determine the state of impairment on their own. Therefore, urine results indicate past use of a drug, and more information is needed to evaluate impairment.

Useful Materials for Review in Toxicology Litigation

Some of the documents that may be useful for Toxicology review are medical records, ambulance records, toxicology results, analytical data, police reports, bar receipts, video, witness statements, and depositions. A Forensic toxicologist can advise and assist in materials that may be relevant during their analysis of the case.

Summary

Forensic toxicologists provide insights into matters involving drugs and alcohol by explaining how the drug or alcohol could have impacted an individual, describe the limitations of the matrix, and can assist with relevant questions for depositions and obtaining Discovery material.

Resources

• Caplan, Y. H., & Goldberger, B. A. (Eds.). (2015). Garriott’s medicolegal aspects of alcohol (6th ed.).
• Couper, F. J., et al. (2024, December 1). Drugs and Human Performance Fact Sheets: 2024 (Report No. DOT HS 813 650). NHTSA.
• Levine, B. S., & Kerrigan, S. (Eds.). (2020). Principles of Forensic Toxicology (5th ed.).

Related Rimkus Content

• Q&A with Amanda Kogelschatz, “Forensic Expertise in Toxicology for Litigation and Claims“
• Article, “What is Forensic Toxicology? Expertise in Litigation and Claims“

Work With a Forensic Toxicology Expert

Rimkus forensic toxicologists provide independent analysis and expert testimony for attorneys, insurers, and organizations handling matters involving drugs, alcohol, and chemical exposure. Learn more about how our team supports litigation and claims on the Toxicology and Food Safety practice page.