Toxicology reports are often associated with criminal investigations, but they also play a major role in civil cases—especially those involving personal injury or wrongful death. When drugs, alcohol, or other toxic substances are suspected to have contributed to an accident or death, toxicology results can become key evidence.

In civil litigation, toxicology findings can help establish liability, defend against claims, or clarify the events leading to a tragedy. These reports can impact everything from settlement negotiations to courtroom decisions, and understanding how they’re used is important for anyone involved in such a case.

We explain how toxicology data factors into personal injury and wrongful death cases, what legal standards apply, and how courts in some states handle these types of evidence in the following article.

What Is a Toxicology Report?

A toxicology report is a medical analysis that identifies the presence (and often concentration) of substances like alcohol, prescription drugs, illegal drugs, or poisons in the body. These tests are typically conducted using blood, urine, or tissue samples, either after an accident or postmortem in fatal cases.

In personal injury or wrongful death litigation, toxicology reports can:

• Show whether a driver was under the influence at the time of a crash
• Reveal the presence of medications that impair judgment or motor skills
• Identify toxic exposure in workplace or environmental injury claims
• Establish whether substance use contributed to negligence

How Toxicology Reports Are Used in Personal Injury Cases

In personal injury cases—especially those involving auto accidents—proving impairment can dramatically shift liability. For example, if a driver was found to have a blood alcohol content (BAC) above the legal limit, this can support a claim of gross negligence or even open the door for punitive damages.

Toxicology findings might also be used to:

• Reconstruct the sequence of events
• Support expert testimony on driver behavior or impairment
• Counter arguments that blame the injured party

Massachusetts Example

In Massachusetts, operating under the influence (OUI) is defined as having a BAC of 0.08% or higher. If a driver involved in an accident tests over this limit, that information can be used to prove fault in a civil lawsuit under negligence per se—a concept that allows a violation of law to serve as evidence of negligence.

Toxicology in Wrongful Death Claims

When someone dies due to suspected negligence, a toxicology report may help clarify what happened—particularly if there are questions about the deceased’s condition or the actions of others involved.

For example:

• In a workplace death, the presence of toxic chemicals or carbon monoxide might indicate employer liability
• If a victim had no substances in their system, it may refute claims that they caused the accident
• A positive test in a responsible party could be used to establish wrongful conduct that led to the death

Toxicology results often play a part in autopsy reports, which can be submitted as evidence in court with testimony from medical examiners or forensic pathologists.

Admissibility and Challenges

While toxicology information can be powerful, it isn’t automatically admissible in court. Several legal hurdles must be met:

• Chain of custody: There must be clear documentation showing how samples were collected and stored
• Qualified interpretation: Results must be explained by a medical or scientific expert, not just introduced as raw data
• Relevance and reliability: Courts may exclude evidence if it’s not clearly tied to the issue of liability or if the testing method is questionable

Defense attorneys sometimes challenge toxicology findings on the basis of timing, dosage interpretation, or potential lab error. It’s not enough to show a substance was present—legal teams must connect the presence to impairment or negligence at the time of the incident.

State Variations and Legal Standards

Toxicology is interpreted under state laws, which can differ in terms of limits, presumptions, and admissibility rules. For instance:

• New Jersey also uses the 0.08% BAC standard, but has added provisions under its dram shop laws, allowing liability for establishments that serve alcohol to visibly intoxicated individuals
• New York permits toxicology results in both criminal and civil courts but requires expert analysis to confirm how the substances would have affected behavior

These differences make it essential to work with attorneys familiar with local rules and how they apply to your case.

When Toxicology Results Make the Difference

Here are examples where toxicology shaped the outcome of a case:

• A trucking company was found liable after post-accident drug tests revealed a driver had unprescribed opioids in their system
• A wrongful death claim succeeded after proving a bar overserved a patron who later caused a fatal crash
• An injury claim was dismissed when toxicology showed the plaintiff had mixed prescription drugs and alcohol before falling at a worksite

In each case, the results didn’t stand alone—they were supported by expert interpretation and linked directly to the claims of fault or defense.

Call Brandon J. Broderick For Legal Help

If you’re involved in a personal injury or wrongful death case where toxicology may be a factor, you need a legal team that understands how to handle complex medical evidence. At Brandon J. Broderick, Attorney at Law, we work with respected experts to analyze toxicology reports, challenge unreliable findings, and build a compelling case for our clients.

Whether you're pursuing justice after a loss or defending against a claim, we’re here to guide you every step of the way. Contact us today for a free consultation.