Expert Witness and AttorneyIntroduction

When retaining and working with expert witnesses, attorneys have a number of matters to consider to ensure that their interactions with such experts are ethical.

This article examines some of the common ethical considerations involved in this dynamic by the American Bar Association (ABA).


Engaging Expert Witnesses

One ethical issue that the ABA deems important is how attorneys go about choosing and engaging the experts they wish to use. See George Carr, “Ethical Considerations in Dealing with Expert Witnesses,” American Bar Association, Feb. 23, 2016, available at (last visited Oct. 25, 2017).

One particular matter that can arise during this phase of the attorney-expert relationship concerns client confidentiality. See id.

One of the model rules crafted by the ABA suggests that client confidentiality must be protected, unless a client has either given an attorney informed consent to reveal that information to another party, or unless such a revelation is authorized by implication. See id., citing Model Rules of Prof’l Conduct R. 1.6(a).

Although an attorney’s involvement in a particular lawsuit is a matter of public record, both clients and their legal representatives are likely to want to preserve the private nature of as much client information as possible.

As the ABA suggests, “Accordingly, it is often worthwhile to discuss with your client, at the outset of an expert search, the parameters of what information can or should be revealed to potential experts when interviewing them and checking conflicts, and whether and when nondisclosure agreements should be proposed or obtained.” Id.

Retaining Expert Witnesses

Another consideration for attorneys in the expert selection process involves how to frame the nature of the retention.

Litigators should not suggest to expert witnesses that they will be hired on a contingent basis—they are hired to provide their opinions but their pay should not be implied to be outcome-dependent. See id.

Therefore, it is important for attorneys to make that clear to the experts they seek to retain, particularly if an expert is not seasoned in the way that certain components of litigation work.

Lawyers should be familiar with each state’s rules on this issue, as many states, such as California, expressly prohibit contingency hiring with respect to experts. See id.

Moreover, as the ABA explains, “[E]ven in jurisdictions where contingent expert fees are permissible, contingent compensation arrangements are likely to impact the credibility of the expert, and may provide a basis to exclude the expert’s testimony entirely.” Id.

Post-Engagement Issues

When an expert is hired, other ethical considerations arise, and confidentiality matters are pertinent at this stage as well. See id.

According to the ABA, “Providing confidential information to an outside expert may violate not only the client confidences learned during the attorney-client relationship, but may also infringe on third parties’ privacy rights.” Id.

Certain cases, particularly those that involve medical issues and are governed by the HIPAA, require that specific steps be taken to safeguard client information. See id.

Similarly, under the Fair Credit Reporting Act, cases involving parties’ credit information may also necessitate special steps being taken to protect client confidentiality. See id.

Attorneys are not the only ones with obligations regarding maintaining confidentiality.

Experts are also under an obligation to do so in many circumstances. See id.

For example, “Most jurisdictions recognize the duty of expert witnesses to maintain the confidentiality of information learned during the engagement.” Id.

Because many experts do not have legal training, it is incumbent upon attorneys to inform such witnesses as to the duties of confidentiality experts may owe particular clients.


Expert witnesses hold the key to many court decisions and have persuaded fact-finders in cases of every type.

Both attorneys who employ experts and the experts themselves should be familiar with the rules governing ethical considerations in their relationship, and in turn, should enjoy being part of an effectively-functioning legal team that best serves its clients.