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Current Developments Relating to Expert Testimony

Wed, 11 Sep 2013
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Published in Articles

The purpose of this paper is to show how the role of an expert witness has changed over the years, due to various factors. Examples will illustrate how experts have gotten themselves into situations that ultimately ruined their credibility. At the conclusion of this course, the student should be able to use the examples provided to avoid the traps while remaining objective in their testimony.

At the beginning of our civil justice system, there were paid witnesses. In other words, if a merchant was accused of cheating a customer, both the merchant and the customer could pay witnesses to testify on their behalf even if the witnesses had no knowledge whatsoever concerning the events at issue. Apparently, this practice was so prevalent that one of the Ten Commandments addressed it by stating “Thou shall not bear false witness against thy neighbor.” As a result standards of evidence evolved so that only witnesses having “personal knowledge” of the event could testify.

For many years, this rule worked very well because the level of technology was low and most everything in everyday life was within the common knowledge of most people. However, as we entered into the industrial revolution, the level of technology increased to the point to where many aspects of society were beyond the common knowledge. As a result, the rules of evidence had to change in order to provide a mechanism to educate fact finders as to technological issues that were beyond the common knowledge. Thus, we had the advent of the “expert witness.”

Expert witnesses could testify even though they did not have “personal knowledge” of an event. The expert witness was to be a neutral person who had specialized knowledge of an area that was relevant to the case. His/her purpose was to educate the fact finder as to technological issues that were beyond the scope of the common knowledge. So instead of testifying as to “facts” the expert would give “opinions.”

One would think that the judge would determine whether expert testimony was necessary and be responsible for determining who the expert would be. For example, if the judge determined that a handwriting expert was needed in a case, the lawyers could suggest names of qualified experts and the judge would choose one. The chosen expert would then examine the facts and circumstances provided to him/her by the attorneys and then formulate an opinion based upon his/her expertise. For whatever reason, this type of system for designating experts was not adopted.

Instead, each party would retain their own expert who would provide opinions on behalf of one of the parties. As a result, many cases resulted in “dueling experts” that required the jury, who does not have the technical knowledge, to determine which expert to believe. This system of expert advocacy was encouraged because the rules of evidence only required that the subject matter of the expert’s testimony be beyond common knowledge of most jurors and that the expert was “qualified.” For example, if a case involved the molecular makeup of a moon rock, an “expert” could testify that it was his opinion that the moon rock was made of cheese as long as he/she had an impressive resume. As a result, “experts” were no longer neutral, but instead became advocates. Moreover, most of the time, they were paid for their testimony. As a result, our civil judicial system regressed back to paid witnesses.

The Advent of the Gatekeeper Concept

The United States Supreme Court recognized the fallacy in expert testimony as it existed. As a result, it addressed the problem in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). In that case, the United States Supreme Court invoked a never before used concept of a judicial gatekeeper in regard to expert testimony. In essence, it required three instead of two requirements:

  1. That the subject matter of the testimony be beyond the common knowledge;
  2. That the expert be qualified to testify about the subject matter; and
  3. The opinions rendered by the expert are reliable.

Daubert, 509 U.S. at 588-89.

The gatekeeper is the trial judge who makes these determinations even before the expert is allowed to testify. Id. at 589.

The key standard that the trial judge has to apply is the concept of reliability. Case law has held that the following factors relate to reliability:

  1. Whether the theory has been tested;
  2. Whether it has been subject to peer review;
  3. Whether the technique has a potential error rate or standard operating procedures; and
  4. Whether a theory is generally accepted within the scientific community.

If the opinions of an expert do not meet the reliability test, the expert testimony is not allowed.

The Transition

Many persons who have offered expert testimony before the days of Daubert understood that they were advocates on behalf of the persons who hired them. In fact, experts were keeping “statistics” as to how many cases their clients had won with their expert testimony. As a result, it was not unusual for experts to have conflicting opinions from one case to another. As a result, these experts were vulnerable to attack as to the reliability of their opinions. Unless they could explain the discrepancies because of updated technology their opinions were, for the most part, excluded.

Federal courts require that experts keep lists of cases in which they have rendered opinions. As a result, it is fairly easy for attorneys to research previous opinions made by an expert in order to attempt to discover discrepancies. In today’s world, an expert should strive for objectivity and consistency. An expert should work to show that he/she is not an advocate, but instead is an objective and knowledgeable person who is there simply to assist the fact finder in determining the real facts.

A Case Study in Disaster

This is a story of an expert who grew up during the “expert advocacy” system and was caught by the change brought on by Daubert. This paper will only use this expert’s first name, even though his complete identity is revealed in a Texas Supreme Court case that has been published.

Ed was a fire cause and origin investigator. He was typically hired by insurance companies to conduct fire scene investigations and render opinions as to whether a fire was accidental, intentionally ignited, caused by a product defect or was undetermined. Typically, when Ed testified on behalf of an insurance company in an arson case, he would almost always render an opinion that the fire was intentionally set. When he was asked to testify in regard to a product defect, he almost always testified that the fire was caused by a defective product. Ed prided himself on the eloquence of his language and his advocacy for the entity that was paying him.

Unfortunately, Ed was apparently too slow to recognize that the “expert advocate” system had died and that he could no longer render any opinion that he wanted to just because he had an impressive resume.

In the case of General Motors Corp. v. Iracheta, 161 S.W.3d 462 (Tex. 2005), Ed testified in a case involving an alleged defect in a car that caused a fire that killed a child. His opinions were that a manufacturing defect in the car that caused gasoline to leak from the fuel system onto the ground caused the car to explode, killing the child passenger. Iracheta, 161 S.W.3d at 464. Unfortunately for Ed, the Texas Supreme Court ruled that his testimony was unreliable. Id. at 471. It chronicled, in great detail, the inconsistencies in his testimony. At the conclusion, the Texas Supreme Court stated “a propecia online
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fair view of his testimony is that he was willing to say almost anything, directly contradicting himself.”

Needless to say, Ed’s career as an expert witness has drastically been affected.

How To Avoid the Traps

The following is a listing of some of the factors that will come into play in order to determine whether the opinions of an expert are allowed. These are not all of them but are ones that may be useful going forward.

Always be objective.

Remember that the role of an expert is no longer that of an advocate, but instead of an objective resource. An expert should be there to render opinions, regardless of the result. For example, even though an expert is retained by one side, he/she should be fully capable and willing to provide opinions to the side who has not hired him/her.

Experts are given factual scenarios and then asked to render opinions based upon those scenarios. An expert should always be just as willing to render an opinion on fact scenarios supplied by the other side and he/she is to render opinions for the side who has hired him/her.

Be prepared to acknowledge the viability of other theories if those theories have been accepted in the field of expertise. Also, to the extent possible, the expert should make himself/herself available to provide expertise regardless of whether it is for a plaintiff, defendant, insurance company or individual.

Money issues.

To the extent possible, receive your compensation before you publish your opinion. Never accept a case on a contingency basis. Be careful of letters of protection. Some doctors will allow their patients not to pay them in a personal injury situation if the patient’s lawyer will agree to “protect” the doctor and pay the bill out of any recovery. Letters of protection come precariously close to being contingency agreements. Doctors who render expert opinions and who have letters of protection can always be attacked as having a financial stake in the outcome of the case.

Always keep a list of cases in which you have testified as an expert.

It is not only a requirement in federal court, but it is a good idea for an expert to keep a list of all cases where he/she has testified as an expert. Also, we recommend keeping copies of any depositions or trial testimony that the expert has access to. Some experts made it a practice to never keep copies of transcripts where they have testified. They thought that this practice would prevent attorneys from discovering what their prior testimony had been. However, in today’s world of digital electronics, there are organizations that have libraries of depositions and trial testimony of experts. An expert that routinely does not keep copies of transcripts will be blindsided during depositions or at trial.

To the extent possible, ground your opinions in accepted methods and procedures.

In today’s world, almost every field of study has an accompanying organization that issues various standards. An expert should know what those standards are, should follow them and should reference his/her reports and testimony.

Know the factors set forth in Daubert.

To the extent possible, the expert should reference the Daubert standards in his/her reports and testimony.


Evidence supplied by expert witnesses has changed drastically. People who offer expert testimony need to know these changes and to adopt them. Ignoring them can result in disaster for the party who retains the expert and can destroy the future ability of an expert to testify. It is our hope that this paper has been helpful.

by Michael Johnston
Johnston Legal Group PC

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