Mesa AZ | Personal Injury attorney Brian T. Allen writes about expert witnesses in the following post:

To win just about any type of case – a criminal prosecution, a personal injury claim, a contract dispute, a civil rights claim – something will need to be proved. In order to prove something, sufficient evidence will be needed. In some cases, in order to provide sufficient evidence, an expert witness will be required.

Expert witnesses are like other witnesses in that they may be called to testify in court or appear at a deposition. However, expert witnesses are allowed to testify about certain subjects other witnesses are not, and give their opinions on these subjects to the court. These subjects include professional standards and codes of conduct, and scientific evidence.  Before a witness can be called an “expert,” and so testify with the special privileges expert witnesses are allowed, he or she must be qualified to do so.

Expert witnesses are tremendously important in most medical malpractice cases. In order to win a medical malpractice claim, a claimant must prove that the healthcare provider did not comply with the “applicable standard of care.” Per Arizona law, to comply with the applicable standard of care means to “exercise that degree of care, skill, and learning that would be expected under similar circumstances of a reasonably prudent” health care provider in Arizona. Notice that this is a two-step process: the claimant must first establish what the applicable standard of care is, and then prove that the healthcare provider did not comply with that standard.

Expert witnesses are key to both steps. For it is typically only an expert witness who can testify as to what the applicable standard of care is, what actions comply with that standard, and what actions do not comply with it. A “layperson” witness cannot testify regarding these subjects.

As stated previously, however, a witness must qualify as an expert witness before he or she can give such testimony. If you are bringing a medical malpractice claim, it is important to understand who can qualify as an expert witness in your case.

The relevant Arizona law is A.R.S. § 12-2604. It is a little long to post in its entirety, but you can read it here. The gist is that in order to testify as an expert witness, a witness’s qualifications must essentially mirror the qualifications of the person he or she is testifying against or on behalf of. In other words, if the defendant is a heart specialist, the witness should also be a heart specialist. Further, the law has requirements regarding the witness’s professional activity one year before the incident that led to the claim, and special requirements for general practitioners.

Finally, the law also includes this provision: “This section does not limit the power of the trial court to disqualify an expert witness on grounds other than the qualifications set forth under this section.” Judges act as gatekeepers; they decide what evidence comes in, and what does not. There are a lot of other grounds outside of this law on which an expert witness could be disqualified by a judge. An experienced attorney can help ensure that you have witnesses on your side who can pass the legal and evidentiary tests to qualify as expert witnesses. Because expert witnesses are so important to medical malpractice claims, the help of an experienced medical malpractice attorney in your case could be key to your success.

This blog should be used for informational purposes only. It does not create an attorney-client relationship with any reader and should not be construed as legal advice. If you need legal advice regarding Mesa AZ|Expert Witnesses in Medical Malpractice or any other personal injury, please feel free to contact Brian T. Allen at  480.461.5335,  log on to,  or contact an attorney in your area. Udall Shumway PLC is located in Mesa, Arizona and is a full service law firm. We assist Individuals, families, businesses, schools and municipalities in Mesa and the Phoenix/East Valley.