Despite the political rhetoric, public confidence in scientists has “remained stable for decades.” You can bring this confidence into the courtroom through expert testimony based on the scientific method, i.e., physical observation and testing, not just untested hypotheses. Experts should be “hands on” when it comes to collecting and investigating physical evidence.
- Have your expert visit the scene. When a case involves a physical site, such as an accident scene, an expert should visit it under circumstances that are as close as possible to those that existed when the event occurred, e.g., time of day, lighting, exact location of persons and objects involved, weather, and noise. The visit often gives the expert new insight into or understanding of the case—he or she may even discover physical evidence not found by others. And, at a minimum, it makes the expert immune from the peripheral cross-examination question: “You’ve never even visited the accident scene, have you?”
- Let the expert study the original evidence. If a case involves tangible physical evidence, e.g., a broken part in a products liability case, a machine in an industrial accident action, or a will in a testamentary dispute, an expert should personally examine, handle, and study the original whenever possible. It’s always possible that the original may have a minor but significant difference, or an original document may have a marginal notation that doesn’t come through on copies. And even if examination of the original doesn’t produce any revelations, it gives the trier of fact an indication of the expert’s thoroughness and adherence to the scientific method.
- Give the expert all documents, not summaries. The expert should be given the original or a copy of every significant writing or other matter on which his or her opinion will be based, not just a summary prepared by counsel. For example, in a medical malpractice case the medical expert should have complete copies of all of the plaintiff’s medical records; accident reconstructionist experts should have copies of all eyewitness statements and depositions; and accountants or economists should have, at least, access to all financial records.
- Have the expert speak with parties and witnesses. If an expert’s opinions will be based on the observations, feelings, condition, and thoughts of the party represented by counsel, or of an available and cooperative witness, the expert should meet and talk with that individual. For example, in personal injury cases the recollection of the plaintiff driver or plaintiffs’ industrial accident victim is crucial to the expert’s opinion, yet plaintiffs’ attorneys frequently fail to have their experts meet the clients, and instead give the expert a copy (or even a mere summary) of the client’s deposition or statement. The expert must then depend on the information elicited by plaintiff’s attorney at the deposition, with no opportunity to make his or her own inquiries. This failure might allow defense counsel to imply that there’s something almost conspiratorial about plaintiff’s case because plaintiff’s counsel wouldn’t even allow his or her own expert to talk to the client.
Giving the expert full access to the evidence and a chance to apply the scientific method has two significant advantages: It allows you to test your expert’s thesis for accuracy, and it provides a firm basis for arguing why the judge or jury should accept the proven opinions of your expert. Your expert’s tested opinions will also be particularly persuasive if the opposing expert’s theories are untested.
For more on following the scientific method with physical evidence, including helpful checklists on relevant trial considerations, turn to CEB’s California Expert Witness Guide §§9.2-9.14. And for a comprehensive discussion of several types of scientific evidence you’re likely to encounter in the courtroom, check out CEB’s Scientific Evidence and Expert Testimony in California.
Other CEBblog™ posts you may find useful:
- Choosing an Expert Witness: Insider or Outsider?
- 5 Steps to Preparing an Expert Witness to Do Battle
- Blinding Them with Science
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