Cross-Examination of Expert Witnesses

Dan Small | Holland & Knight

Cross-examining an expert witness can be a dangerous undertaking. By definition, the person you are examining knows a great deal more about this subject than you probably do. Plus, they are likely to be an experienced and clever witness, being highly paid to do you harm. There are landmines everywhere, but if you pick your spots carefully, you may be able to land some hard blows. That said, your cross has to be carefully thought out and well prepared.

Here are some typical areas of expert cross-examination:

  • First, lack of qualifications. For example, a physician who is not board certified in the particular specialty.
  • Second, unrelated qualifications. Most fields of expertise are specialized, legally specialized or professionally specialized. A brain surgeon may not know much about knee replacement.
  • Third, lack of experience. An expert may have an impressive academic background, but little real hands-on experience in the specific issue in the case.
  • Fourth, bias. For example, the expert always testifies for medical malpractice plaintiffs, or even worse, always testifies for the other side’s law firm.
  • Financial interest. For example, the expert advertises their services for a fee, and that fee is most of their actual income.
  • Faulty data or a lack of data. Incorrect assumptions of fact. Incomplete knowledge of the facts of the case.
  • Faulty reasoning. Prior inconsistent statements. You need to know everything that expert has ever said on the subject at hand. Opinions that are contrary to statements in well-regarded treatises or opinions that are contrary to the expert’s own statements. 

And much more.

And here are some of the rules to follow when examining an expert witness.

First, never attack an expert in their area of expertise unless you have no other choice and you are appropriately prepared, or you are confident you can score points. Otherwise, you may just give the expert a chance to sit back, relax and impress the jury with how smart he or she really is.

Second, sidestepping an expert’s opinion by attacking its factual basis is usually preferable to trying to hit the opinion head on.

So, Mr. Expert, your opinion is based on assumption X, correct? And if it turns out that assumption X isn’t true, then your opinion would be different or no longer valid, right?

Or: So Mr. Expert, you only read the parts of the record that plaintiff lawyers fed you.

Or: So, Mrs. Expert, you read the deposition of the plaintiff, but you didn’t read X, Y and Z.

Number three, don’t attack everything. When everything is important, nothing is important. Besides, there may be parts of the opposing expert’s report or opinion that you can live with, or that you can even turn to your advantage. There may be things that your expert says that you can get their expert to agree with.

Fourth, sit down and shut up. Once you’ve made your points, sit down. The more time you give an expert to talk, the more he’ll talk or she’ll talk, and the more they’ll bolster their original testimony. One of the cardinal rules of cross-examination is to avoid repeating and reinforcing the direct examination. That rule applies exponentially with expert witnesses.

Number five, remember that most of the time you’ll have an expert too. You don’t have to destroy your opponent’s expert. Just score the points you can and give your expert what they need to criticize their expert and give your expert room to make their points when their turn comes.

Finally, number six, remember the first rule of cross-examination. It’s the same as the first rule of medicine. First, do no harm. Don’t risk making your case worse by grasping to achieve something beyond your reach. That’s all.


When one of your cases is in need of a construction expert, estimates, insurance appraisal or umpire services in defect or insurance disputes – please call Advise & Consult, Inc. at 888.684.8305, or email experts@adviseandconsult.net.

Leave a Reply

%d bloggers like this: