Strategies for the Cross-Examination of Experts

In my last post, I discussed what a trial attorney can do to prepare for the cross-examination of an adverse expert. Below are some strategies that can be used in successfully cross-examining an adverse expert witness:

1. Favorable Evidence: One tactic that should not be ignored is using the opposing party’s expert to concede to facts favorable to your side of the case. These could include the fact that your client was injured by a motor vehicle collision, that there is no evidence that your client is a malingerer, that your own expert is well-qualified or well regarded in the community, etc. You can use the expert to corroborate the propositions which make up your expert’s opinion or reasons. This is why it is important to make sure you have the expert’s report and/or have taken his deposition. In this way you will know in advance whether the expert will agree with the proposition you want to prove. It is best to prove these favorable points before attacking the expert as he may be less willing to concede a point once you have attacked him as being biased.

2. Narrow the Expert’s Apparent Expertise: This is where having the expert’s curriculum vita (resume) in advance is important. If the accident reconstruction expert is self-taught or never went to college you may want to prove that he does not have a degree in mechanical engineering, in fact he has no degree at all, or the expert is not a certified professional engineer or a medical doctor and could not sit for a board examination even if he wanted. You can prove the expert has never taken engineering calculus or college physics, etc. If the expert is a psychologist, you can contrast his inability to prescribe medications with that of an actual medical doctor such as a psychiatrist who may do so.

3. Varying the Hypothetical: Inquire into the basis for or the underlying assumptions supporting an expert’s opinions and then ask the expert if the evidence showed “X” if this would change his opinion. Before asking such questions it is usually important to anchor the underlying principles and rules the expert is utilizing in analyzing the evidence and rendering his opinion. For example, I remember a neuropsychologist I cross-examined about his opinion that his patient had suffered permanent brain injury and brain atrophy as the result of a traumatic blow to the head. The Diagnostic and Statistical Manual used by the expert indicated that to make a differential diagnosis, one had to rule out other causes for these symptoms such as long-term abuse of alcohol. The expert agreed with these principles and the need for an accurate medical history to make an accurate opinion as to the cause or etiology of the patient’s symptoms. I asked him: “Would such information be important to know? Yes. Would the medical history affect the accuracy of his diagnosis and opinion? Yes. Later in his deposition, I looped back and confronted him with medical records establishing the patient’s long term abuse of alcoholism and his treatment for alcoholism. The expert agreed this evidence was important and ultimately withdrew his opinion after being presented with evidence of chronic alcoholism. Had he refused to concede this point, I would have argued to the jury that the expert did want to be confused by the facts as his mind was made up. The jury would have seen this expert as narrow-minded and dishonest.

4. Have the Witness Define Technical Terms: “Pull back the curtain” as Toto did in the Wizard of Oz and make the expert put his statements in simple plain English if a clearer understanding of the term is helpful to your side of the case. Experts love to speak in technical jargon that dresses up their testimony for very simple events. For example, if the doctor testifies that the witness had a “contusion” on his arm, then point out that this is just a fancy term for a “bruise”. This removes the mystery behind the expert’s testimony and allows the jury to make their own assessment instead of blindly relying on the expert.

5. Typos, Spelling and Math Errors: If the expert’s report has such mistakes, first show important it is for the expert to pay attention to detail and carefully review his opinions before submitting a report, then bring out these errors on cross. You can also have the opposing expert spell long complicated terms for the benefit of the court reporter. Sometimes experts will be unable to accurately spell such terms. If he stumbles you can continue to do this as the deposition precedes. If you suspect that the expert is using a computer program to do his calculations and is “math illiterate” provide him with a calculator and have him vary the input data and recalculate the speed of a vehicle or its stopping distance. Oftentimes experts are unable to do the calculations at all. You can later argue “sloppy in, sloppy out” or “garbage in, garbage out” or that the expert really is not very “expert”.

6. Use the Expert to Criticize His Own Client: Sometimes an opposing party will do something in a fashion that is not safe or wise. It could even be on a topic the expert was not hired to assess. Use the expert, to show that the procedures used by his client were unsafe, improper or ill-advised. This is especially useful if you know the expert will have to agree or look biased and/or stupid to contest such a proposition. Some experts will try to dodge the question by saying “I was not hired to make that sort of analysis”. Don’t let them side step your question and demand that answer “yes, no or I have no opinion”. If they say that they have “no opinion”, you can show that is something the other party (the expert’s client) could have asked the expert to analyze, but did not.

7. Lack of Firsthand Knowledge: Demonstrate the expert lacks firsthand knowledge. It may be a defense medical examination where the doctor saw your client only once or perhaps he is basing his opinion solely on his review of the medical records. In contrast, your client’s doctor has seen him over an extended period of time on numerous occasions. Ask the expert “It is always preferable to see a patient many times over an extended period in evaluating a person’s condition?” If you think it is unlikely he will agree with this, you can ask: “Was the plaintiff seen on this date by his own doctor and examined? Yes. Your examination of the patient was limited to single occasion. My client doctor saw him over 25 times? Yes. Over twenty-four months? Yes. You have to accept my client’s doctors observations as true because you were not there? You are limited to what is contained in the records? Yes.

8. Show the Expert’s Opinion is Based Upon Unreliable Evidence or Rests Upon the Truthfulness of a Questionable Source: If you can show that a witness relied upon by the expert is mistaken, inaccurate unreliable, or lying, then have the expert concede that this type of information is important to the accuracy of his opinion and that he is accepting this information as true, accurate and reliable. You can ask: “Unlike you, the jury will be able to evaluate the witness’s demeanor and credibility when they testify? Yes. Again you can use the “garbage in, garbage out” approach in closing to undermine the expert’s opinions if you can establish the supporting data is not reliable.

9. Lack of Thoroughness: Demonstrate that there are more tests the expert could have performed to get more accurate data to use in his analysis. This could be things such as the expert could have used a similar vehicle to figure stopping distances, that the expert failed to actually test the road’s surface to find the “actual” coefficient of friction instead of just taking some number out of a text-book or guessing.

10. Financial Bias: If the expert at issue has testified for the opposing party, attorney or insurance company before, point out how much money this relationship has generated for the expert or that the expert is a “whore” or a hired gun for the “defense” or “plaintiff”. You can use tax or business records to show this financial bias.

11. Inconsistent Positions: Find similar cases where the expert has testified on the opposite side of the issue. Use this inconsistency to show that the expert is not a scientist, but is rather an advocate for whichever side hires him. Use the expert’s own articles or writings to undermine contrary positions he has taken at trial.

12. Confront the Expert with Authoritative Materials: As mentioned in the earlier post, look for textbooks or journal articles you know the expert will have to agree are authoritative and reliable. You can read favorable points in during cross in support of your position under Rule of Evidence 803(18). This hearsay exception provides:

(18) Learned Treatises. To the extent called to the attention of an expert witness upon cross-examination or relied upon by the expert witness in direct examination, statements contained in published treatises, periodicals, or pamphlets that contradict the expert’s testimony on a subject of history, medicine, or other science or art, established as a reliable authority by the testimony or admission of the witness or by other expert testimony or by judicial notice. If admitted, the statements may be read into evidence but may not be received as exhibits.

I hope these thoughts are of use to you the next time you take on an adverse expert witness. I would appreciate hearing of any strategies you may have. Good luck!