Irving Younger wrote the “Ten Commandments of Cross-Examination” in 1976. These ten points are probably still as central to an effective cross examination of an expert as they were then. Here is some elaboration on what usually works, and what seldom works.

  1. Be Brief

The objective of cross examination of a liability expert is not to attempt to refute every point the expert has made on direct examination. The objective is to cast significant doubt on the credibility of the expert. This can only be accomplished by addressing the credentials, assumptions and opinions that the expert has testified to that you KNOW you can demonstrate are not worthy of the jury’s belief. When preparing for cross, every question should be analyzed to see which of those three things are challenged. If there is any significant doubt of who will win the point, leave the question on the cutting room floor. The cross of a tough expert should seldom take more than one quarter of the time that was taken on direct. If you find that the cross is going to take longer than that, you should seriously consider cutting it back. Going on too long is one of the two most frequent causes of an unsuccessful cross examination.

  1. Use Plain Words

If the only people in the courtroom who realize how effectively you have “gutted” the opposition’s expert are you and the expert, then the expert has won and you have lost. Your ability to smoothly demonstrate that you have a true mastery of the subject that you are discussing with the expert, while satisfying to you, is of no benefit to the jury. You must reduce the issue you are addressing to a knowledge level that will convince the jurors that what the expert has sold them on direct is inconsistent with the common sense that you will be emphasizing they need to use to decide the case in closing argument.

  1. Use Only Leading Questions

Everyone knows this rule, but everyone also fails to follow it diligently. If you doubt that, go back and look over the last cross examinations you have handled. While looking for the places where you failed to keep the ball in play with only leading questions, look for where the cross fell apart. It will almost always be where you allowed the expert to take control of the traffic and begin to explain what she had already carefully explained on direct examination. Good experts have probably spent several times as many hours on cross in a courtroom as you have. They are ALWAYS waiting for you to give them an opportunity to reiterate their favorite themes.

  1. Be Prepared

The risk of extensive preparation is the tendency to show the jury all that you know. That can lead to a lengthy, tedious cross that does not capture the jurors’ attention. Preparation includes distilling the key points and determining how to convey them. When you have prepared for hours or days to destroy an opposing expert, you become captivated by how powerful your carefully crafted outline is. And not using every single question seems to leave some of your great ideas at home. But the jury is not nearly as well-versed in the technical issues as you are, and it is not likely you are going to bring them up to speed with your cross of an expert. Save that effort for when you have your own expert on the stand and she is willing to cooperate in your educational endeavor.

  1. Listen, Listen, Listen

Failing to listen to the answers you are getting is the next most common pitfall. The jury will be instructed in virtually every case that the questions are not evidence, only the answers are. The jury also knows that when cross examination starts, the essential point they need to watch for is who is winning the credibility contest. If the expert’s answers appear to defeat the credibility challenge posed by your questions, then you have lost and the expert has won. Often what the expert says in response to a great question will provide the most powerful next question in your cross. The expert may provide an even more perfect setup for your next question than your question did.

  1. Do Not Quarrel

It is very important for you to remain the “good guy” who is confronting the evil expert. If someone is going to quarrel, it should be the expert. Your conduct should always remain respectful. There is nothing gained by appearing to become angry and frustrated by the expert’s unwillingness to concede points that she should obviously concede. The jury is essentially being asked during cross examination to pick a side between you and the expert. That means your side must come across as reasonable and polite. If you find yourself getting upset or emotional, it probably means that you know you are losing the debate, and it may mean it is time to think about stopping!

  1. Avoid Repetition

Avoiding repetition prevents the expert from fixing an answer that he has previously given and would like an opportunity to correct. Asking a question more than once is frequently the mistake that destroys much of the impact of the expert’s first great answer, before he had the opportunity to consider how to better position that answer. The jury hates repetition anyway because they are tired enough of the trial and don’t want to watch the same hand played again. The “Be Brief” rule is hard to comply with if the same subject is covered several times.

  1. Disallow Witness Explanation

If you are careful about using leading questions, you will substantially limit the likelihood of the expert being able to successfully say that he “needs to explain.” Test each question in your outline by asking, can you successfully cut the expert off to a “yes or no”? If not, consider whether that question should be dropped or recast. Usually, it will take several narrative answers before you can expect the judge to step in and instruct the expert to respond, but asking for the judge’s help (if you get it) sends a powerful message to the jury that the expert is trying to be evasive.

  1. Limit Questioning

Many trial judges create their own rules of courtroom behavior. Some of these can be onerous, imposing time limits on examination and otherwise restricting the courtroom latitude of trial attorneys who have become accustomed to a more generous approach. Some rules may affect what you are allowed to do on cross examination. In some jurisdictions, cross is strictly limited to the scope of direct. In others, cross is “open” and can be directed to any subject that is relevant even if not addressed on direct. In most jurisdictions, re-direct is limited to matters that were covered on cross. If you are careful about not opening up subjects that you know are likely troublesome, you may be able to prevent questions on those subjects during re-direct.

  1. Save The Ultimate Point For Summation

Remember how important the last 5 or 10 minutes are to a good movie. The ending is what everyone always takes away. If the last area of questioning “finishes off” the expert’s credibility, you have one. If the ending is flat, or the expert scores some big points, it is likely that the jury will conclude that the expert won the battle.