Along with fact witnesses, a majority of personal injury claims will require expert witnesses. An expert witness explains a certain topic that is outside common knowledge. Examples include medical treatment, accident reconstruction, engineering of a product, and trucking regulations. The expert witness utilizes his or her specialized skills and knowledge to explain to the judge or jury whatever is outside common knowledge. Information about experts and the discovery process dealing with experts prior to trial is explained below.


Not all experts are trained in a science field such as medicine or engineering. An expert is anyone who posses technical or specialized knowledge. Section 40-656 determines who is considered an expert under Kansas law. An expert can be qualified by skill, knowledge, training, experience or education. For example, a mechanic may be considered an expert if he or she has worked in an auto repair shop for several years and knows how a vehicle runs. Additionally, the area of expertise may be anything outside common knowledge. In Kopia v. Genie Co., a witness was qualified as an expert on knots under a federal standard. The expert testified about the sufficiency of a particular knot on a garage door safety device. This case illustrates that the needs of each case will determine what type of expert is needed.

Although a wide number of people can be experts, a select number of people commonly testify as experts. These experts are most prominently seen in the medical field. Generally, these types of experts only testify for one side (either plaintiff or defendant) of litigation and use the same research or conclusion to support their opinions. On the other hand, some experts will testify for both plaintiffs and defendants and may contradict their earlier opinions in cases by using conflicting research. Furthermore, it is common for frequent parties in litigation (such as insurance companies) to retain a medical expert to testify for each injury claim as needed.

On a number of occasions, lawyers consult with an individual about a case with no intention of ever calling on that person to testify. These individuals are not considered expert witnesses because they are not witnesses at all. The law protects these individuals from discovery based on protections the law gives lawyers in preparing for trial. Nevertheless, the information obtained by these individuals by the lawyer can only serve a limited use. For example, a lawyer cannot use the obtained information from the individual to inform the jury of a certain topic. However, the law does not prevent the individual from directing the lawyer to a particular research report or published source that can be used to explain a certain topic to the jury. Nonetheless, these sources contain their own challenges and are generally recognized as not as effective an expert witness explaining the information to a jury. Therefore, it is most beneficial to utilize an expert witness.


Certain special discovery rules apply to expert witnesses. The first rule is that all experts are only potential experts until the court has ruled otherwise. A deadline by the court is normally set to disclose experts. If the court does not set a deadline, K.S.A. 60-226(b)(6)(C) states that all experts must be disclosed at least 90 days prior to trial. Disclosure of expert requires stating the expert’s name, explaining what the expert will testify about, explaining the substance of the expert’s opinion and the why the expert is qualified to give an opinion. All of this information gives the opposing party a heads up on whether or not they need to find a competing expert witness. If an expert is not disclosed in at least 90 days, the likely result will be the expert being prohibited to testify at trial.

Once an expert is disclosed to the opposing counsel, an experienced lawyer will begin researching the expert. The lawyer will want to find the research that the expert is going to rely upon and then potentially present it to another expert. A lawyer can attempt to prevent the expert from testifying by either attacking the expert’s credentials or attack the expert’s method in determining his or her conclusion. Generally, it is easy to attack the expert’s methods if he or she is a licensed doctor. For example, there are several competing theories on the best way to diagnose a concussion and how to determine the cause of a concussion. If a lawyer was able to prove that the methods by the expert licensed doctor was not reliable enough, the court will not allow the expert to testify about the concussion at trial. Similarly, if the lawyer is able to show that the expert’s education or experience was insufficient, the court will not allow the individual to testify at all because the individual is not considered an expert. Both these challenges to an expert are called Daubert challenges after the case Daubert v. Merrell Dow Pharmaceuticals.


Along with testifying at trial, expert witnesses are also required to be available during depositions. In Hagedorn v. Stormont-Vail Regional Medical Center, the Kansas Supreme Court held that the purpose of deposing experts was to make sure that the opposing lawyer knew what to expect from the expert at trial. Deposing the experts is important because it is likely the opposing lawyer does not know the specialized knowledge of the expert. Therefore, the purpose of deposing the expert is to find out how the expert reached his or her conclusion.

A lawyer will emphasize an expert’s credentials and methods for arriving at his or her conclusion at an expert deposition. Therefore, common questions one would hear at an expert deposition involve questions relating to the expert’s education and experience. These types of questions define the “scope” of the expertise and determine what information the expert can testify. For example, a general dentist could testify a patient’s reason for needing oral surgery but the general dentist would not be able to testify about the procedure of actually performing the oral surgery—an oral surgeon would be needed for that information. Another common question one would hear at an expert deposition would be questions related to the methodology used by the expert. These methodology questions would include questions about how commonly used the methodology is, the method’s failure rate and conflicting methods. Similar to the goal of the expertise questions, the goal of the methodology questions is to determine the reliability of the methodology