Trials are fascinating. People love to watch them. Crime dramas, police stories, and shows that feature the ins and outs of a law firm, and the lawyers that make it work, have filled prime time TV for generations. Just about everyone has their favorite. Trials, which form a big part of each, are just as interesting from the inside. In New York, there are intricate rules of evidence; the subtleness of persuasion without overt argument, as in a finely hewn opening statement; the art of insightful cross examination; and the passion of a good closing argument. But one of the most often misunderstood aspects of the trial is the expert witness, and the role she plays in persuading a jury and winning the case.
Every trial has witnesses. Some give live testimony. You get to hear what they say as they say it; watch their facial expressions and their body language as they testify; actually see how they react to tough questions. Others merely have their deposition testimony read. You get to hear a lawyer read what the witness testified to when she was deposed, when the attorneys questioned her before the trial even began; not exciting, but often necessary. Witnesses most often testify about facts, about what they saw, what they heard, or what they did. The reason for this is fairly simple: When witnesses testify falsely about facts, it is much easier to show they are lying, and to punish them accordingly, than if they testify falsely about their opinion. See Ferguson v. Hubbell 97 NY 507 (1884). It is one thing to show that an opinion is wrong; it is much more difficult to demonstrate that the person who gives an opinion does not really believe it.
Sometimes witnesses can testify as to their opinions. An expert witness can offer her opinion about why certain things happened. When a case involves an important matter involving art, science, or technical knowledge that requires special skill or knowledge that the average person does not normally have, an expert is allowed to give her opinion to help enlighten the court and the jury. An expert will not be permitted to offer her opinion at trial merely because she has greater knowledge or experience in a given area than the average juror. Her opinion also has to help clarify an important issue which is beyond the understanding of the average juror. See De Long v. Erie Cnty., 60 N.Y.2d 296, 307, 457 N.E.2d 717, 722 (1983). In other words, it’s not enough that an expert is an expert; the jurors must need her opinion in order to be able to make informed judgements upon something that is beyond their knowledge and understanding.
Many cases in New York point out an obvious, and well-placed, bias toward allowing jurors to make up their own minds, to draw their own conclusions if possible, on the evidence before them, without the opinions of experts. J. Erie, a long time ago, speaking for the Court of Appeals in Ferguson v. Hubbell, 97 N.Y. 507, 513-514 (1884), said it best:
Better results will generally be reached by taking the impartial, unbiased judgments of twelve jurors of common sense and common experience than can be obtained by taking the opinions of experts, if not generally hired, at least friendly, whose opinions cannot fail generally to be warped by a desire to promote the cause in which they are enlisted.
There is a lot of truth in those words. It is easy to look at an expert as nothing more than a hired hand, who gives an opinion not because she believes it but because she thinks it will get her hired the next time; that is a common line of cross examination.
Sometimes, however, jurors will need expert testimony to fully understand how and why something happened. The expert testimony of a forensic accountant might be very helpful to a jury trying to figure out where the money went in a Ponzi scheme, or whether a business that made a fidelity claim because an employee allegedly stole money, actual had money taken from it. A jury trying to determine whether an insured intentionally set fire to his house or business to collect the proceeds of his homeowner’s, landlord’s, or business owner’s policy of property insurance, first has to decide whether the fire was intentionally set; it’s difficult to intentionally set an accidental fire. The testimony of a cause and origin expert, about what caused the fire, whether an accelerant was used, whether all accidental causes of the fire had been ruled out, or even where the fire actually started, probably would greatly aid that jury.
Even when an expert is allowed to testify, because her special knowledge and understanding is needed, a New York jury is not bound to accept the expert’s conclusions; it can disagree with her findings. Allowing the jury to watch and listen to the expert as she gives her opinion, how it was reached and what it was based on, and having the jurors compare it to all the other evidence presented at the trial, allows them to use their common sense and experience to make up their own minds. Perhaps that’s the best approach. After all, an expert is not right just because she is an expert, but neither is she inherently wrong merely because she is an expert. Her opinion should be judged, just as all the other evidence in the trial is, by the jury.