An expert witness has the potential to make or break a case.

An expert witness is a witness who possesses knowledge or experience of a specific field or discipline beyond that to be expected of a layperson. This allows them to give testimony concerning an issue that requires expertise to understand. Experts are qualified according to many factors, including how long they have practiced in their respective field, published works, certifications, licensing, training, education, and peer recognition.

The duty of an expert witness is to give the court an impartial opinion regarding matters of the case for which their expertise has been called.

In the U.S., under the Federal Rule of Evidence 702 (FRE), an expert witness must be qualified on the matter of testimony. Under the rule, a witness qualified as an expert by knowledge, experience, skill, training, or education is able to testify in the form of an opinion or otherwise if:

1. the expert’s technical, scientific or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
2. the testimony is based on sufficient facts or data;
3. the testimony is the product of reliable principles and methods; and
4. the expert has reliably applied the principles and methods to the facts of the case.

Attorneys may use a variety of databases and expert directories when searching for an expert witness. Comprehensive investigation of an opposing expert witness' professional and personal background is a standard procedure for litigators, as failure to vet one's own expert properly could even result in professional liability exposure, such as a negligent retention claim.

Here are some places to begin your search for an expert witness:

1. Research subject matter relevant to your case.

Reference peer-reviewed publications, articles written for major publications, and trade association websites to identify thought leaders and respected professionals in any space. You should also have a general understanding of the topic relevant to your case in order to vet trusted experts and determine if their opinion helps support your case.

2. Leverage search engines.

Elevate your search with details, locations, or other parameters relevant to your case. Make use of key phrases to narrow your search and beware of sponsored listings.

3. Work with expert witness directories.

You can often consult local bar associations for their local expert witness directories. These are typically more affordable, easy to access, and location-specific. However, the experts are often charged a listing fee to be placed on these directories, so there may be limits to the numbers of experts available.

4. Consult expert witness referral services.

Expert witness referral services can significantly lessen the burden of finding experts. The professionals are trained in connecting attorneys and litigants with experts who are custom-picked to meet a certain set of specifications. This is especially helpful if you’re looking for an experienced expert with a highly specific field.

Expert witness referral services have access to expansive databases of qualified experts across industries and practice areas, as well as other search tools that are not commonly available. Thus, you’ll increase your likelihood of locating an expert perfectly suited to the needs of a specific case.