How To Cross-Examine An Expert Witness

The need to cross-examine an expert witness arises most often during the proceedings of a civil or criminal trial, when the expert is offered by the opposing side. If the expert has testified in your favor there would obviously be no need to cross-examine. Many matters during litigation are beyond the knowledge of most jurors or judges. There are certain areas where the training and experience of an expert is required to explain critical information relevant to the issue. When one attorney offers the testimony of an expert to support his case, then the other attorney will have the opportunity to question the opposing expert in what is called cross-examination.

Reserch The issue


Research the issue that the expert will address. Any attempt to cross-examine an expert without preparation would be a futile endeavor. If someone is deemed an expert, the cross-examiner can assume the expert is far more knowledgeable about the subject. The cross-examiner needs to have researched the issue. Thoroughly understand the issue and all relevant evidence. All relevant documents, reports, records and so forth need to be reviewed and highlighted. In essence, there should be no surprises.

Find Ways To Discredit The Expert

Find any way to discredit the opponent's expert. In most litigated matters, it is usually one expert disagreeing with another expert. Sometimes the best way to support your position is to discredit the opponent's expert. Some experts may have testified only for defendants 90 percent of the time. Some experts have committed malpractice or been disciplined by their fellow professionals. Many times there is inconsistency in an expert's prior report or testimony. Anything presented that can discredit the expert will make your expert seem more credible than the opponent's expert.

Rely On Industiry Publications

Research relevant industry publications. There are professional publications addressing almost any matter where an expert would be needed. These publications are research studies prepared by other experts in the field to educate and inform professionals of pertinent findings. There are manuals and guidebooks as well. Some of the instructions and findings in these recognized publications may contradict the expert's opinions. If the publication is recognized, then the cross-examiner can question why that expert's opinion differs from what is found in these professional manuals or research studies. The key is to get the expert to agree that the publication is generally accepted and relied upon by professionals in the field.

Consult With Your Expert

Rely upon your own expert. By the time you cross-examine the opponent's expert, you should have retained your own opposing expert. The expert to be deposed will have most likely prepared a written statement provided in discovery. Your expert will be familiar with all documents, photos and any records. Remembering that the opposing expert is more knowledgeable about the subject than you, go over all the facts and relevant technical issues with your own expert before the deposition. Your expert can point out essential flaws in the opponent's position, and will have key questions to submit in hopes of discrediting the opponent's expert.