What is an Expert Witness?

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Expert witnesses provide crucial and sometimes case-making insights during the legal process, but what exactly do they do? And how does one become an expert witness? Here’s your quick overview of an expert witness’ role in the judicial process.

Expert Witness Definition

An expert witness is a person with in-depth knowledge or experience related to a specific topic that goes beyond the knowledge of a general layperson. In a trial or legal proceeding, the expert witness often has to provide a detailed accounting of their history and experience to demonstrate why they are qualified to provide expert testimony on the matter.

Examples of expert witnesses could include accountants or other financial professionals if the case at hand is related to financial fraud, or doctors or medical professionals in a personal injury or medical malpractice case. The plaintiff or defendant hires an expert witness to bolster the client’s case and provide a deeper dive into the issues at the center of the case.

Responsibilities of an Expert Witness:

No matter which side hired the expert witness, their ultimate responsibility is to the court, not the party paying their fee.

  • The information they provide must be unbiased and objective.
  • Expert witnesses must offer sound testimony and evidence that is based on fact and truth.
  • If a matter or question falls outside the scope of their expertise, they must acknowledge it.

Expert witnesses participate in a trial or legal process to provide unique insights related to the disputed matter based on their specific experience. They must be neutral throughout the process and focus solely on offering information and expertise based on their background.

Hiring an Expert Witness

Hiring an expert witness is not something to take lightly; it requires research and vetting to ensure the witness has the necessary qualifications and background. You can review their academic history, professional credentials, work experience, and any past work as an expert witness. You can also ask for references and information on past cases they participated in as an expert witness.

Trials are a high-stakes environment, so the expert witness has to know what they’re getting into. For that reason, many opt to hire an experienced expert witness, rather than someone who has never provided expert testimony. If you’re hiring someone with less courtroom experience, be sure to fully prepare them for what to expect.

How to Become an Expert Witness

A person in any profession can become an expert witness since litigation encompasses a vast range of case types.

First and foremost, expert witnesses must have significant experience in their field, likely decades of professional history working in their specialty. Many expert witnesses also have advanced degrees or certifications, demonstrating that their knowledge goes well beyond what a typical professional in their field would have. In-demand expert witnesses have also won awards, published articles or other high-level pieces in well-known publications, been interviewed as subject matter experts, or presented at industry conferences or events.

Because expert witnesses have the distinct task of taking complex topics and effectively communicating them, they must be strong, confident communicators.

Expert Witness Services in California

If you are interested in hiring a legal expert witness, Tim McGonigle has extensive experience in the area. As a long-term, highly-regarded attorney in California, he has served as an expert witness on numerous legal matters.

Feel free to reach out to The McGonigle Law team with any questions.


The information contained herein is for general purposes only and does not constitute legal advice.

“When Tim and his staff took on my case, they had hurdles created by former counsel to overcome. Even with all that was working against us, Tim and his staff used their considerable gifts and skills to successfully resolve the case.“

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