United States: Expert Witnesses in Patent Litigation

You can choose your friends, but you can’t choose your relatives. Expert witnesses and fact witnesses are the same way. The fact witnesses who tell your story at trial are like the relatives who join you for Thanksgiving dinner; they come from a limited pool. But, the explosion of patent litigation has created a cottage industry of rocket-scientists, number-crunchers, and legal-pundits eager to offer an opinion for a fee. As a result, there are more choices than ever when it comes to retaining expert consultants and witnesses. But, be careful. Choosing an expert can be one of the most critical strategic decisions you will make in the course of a litigation. Choose your experts wisely, and they will take you far. Make a mistake, and you will regret it all the way through appeal.

Expert witnesses differ from fact witnesses primarily in that experts are given wide latitude to give opinion testimony, even when their opinions are not based on first hand knowledge or observations. In particular, the Federal Rules of Evidence provide that if "scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion." The expert’s testimony must be "based upon sufficient facts or data" and "the product of reliable principles and methods." The expert must apply "the principles and methods reliably to the facts of the case." In today’s patent litigation, where patent owners and accused infringers fight over technologies ranging from active matrix displays to zymogenic cells and, it seems, everything in between, expert opinion can play a crucial role in helping judges and juries to understand and to resolve critical issues in the case.

Experts also can play an important role in helping to develop the theories of your case, and in anticipating the other side’s strategies. Good experts become key members of the litigation team. So, selecting an expert with whom you can work cooperatively to help you understand deeply the technical issues underlying your case, and to develop your claims and defenses, is as important as finding an expert who will be a persuasive teacher at trial. In fact, a compelling expert who can convince even the other side of his point of view can help drive a case to settlement.

In 1993, the Supreme Court of the United States ruled that trial courts must act as gatekeepers to exclude unreliable expert opinion. In particular, in Daubert v. Merrell Dow Pharmaceuticals, the Supreme Court directed that, when considering whether to admit expert testimony, the trial court should consider whether the theory or technique upon which the expert testimony is based can be tested and whether it has been subjected to peer review and publication. The trial court also should consider the potential error rate associated with the theory or technique and whether it enjoys "general acceptance" in the relevant scientific community. Prior to Daubert, most trial courts allowed expert testimony only when based on "generally accepted" scientific theories or technique. Six years later, in Kumho Tire v. Carmichael, the Supreme Court clarified that the standard it pronounced in Daubert applies to all expert testimony, not just scientific testimony, and the year after that Congress amended the Federal Rules of Evidence to accommodate more clearly the Daubert standard. In today’s patent infringement litigation, therefore, not only must scientific experts offering opinions concerning patent infringement and validity meet the Daubert standard, but so too must damages experts opining on lost profits and reasonable royalties, as well as patent law experts pontificating about the duty of candor and patent unenforceability.

But, an expert may not simply arrive at trial and offer opinion testimony that was not previously disclosed to the other side. To the contrary, the Federal Rules of Civil Procedure require the parties to disclose to one another in advance of trial, and at a time usually set by the trial court, the identity of any witness who may be used to present expert opinion testimony at trial. The disclosure must include a written report containing a complete statement of all opinions the expert intends to express at trial and their bases, as well as all the data or other information the expert considered in forming the opinions. The expert’s report must identify any exhibits he intends to use to summarize or support his opinions and list the expert’s qualifications, including a list of his recent publications. Further, the expert’s report must identify the expert’s compensation and list any other cases in which he has testified as an expert within the preceding four years.

In addition, the parties typically depose one another’s experts following the exchange of these reports. There are two basic theories concerning expert depositions. Some attorneys depose experts solely as a discovery mechanism to make sure that they understand all of the expert’s opinions entirely, as well as the complete bases for those opinions. These attorneys save their cross-examination for trial, in an effort to avoid giving the expert the opportunity to prepare for cross-examination. Other attorneys view expert depositions as their best opportunity to undermine the expert. They ask the expert few open-ended discovery questions, and focus instead on leading and hypothetical questions intended to demonstrate that the expert’s theories are flawed, the expert misapprehends the facts, or the expert has improperly applied his theories to the facts. In either case, after the parties exchange expert reports and depose one another’s experts, rare is the expert who offers at trial an opinion that takes either side much by surprise.

Expert consultants, on the other hand, are "behind the scenes" team members who work with attorneys to understand and to develop the case. Since they work confidentially with the litigation team, much or all of the work they do enjoys protection from discovery as attorney work product (although the rules do provide that an expert consultant’s work can be discovered under "exceptional circumstances"). Attorney work product protection can be lost, however, by disclosing a consultant’s work to a testifying expert. In that event, to the extent that the consultant’s work forms any of the data or information upon which the testifying expert’s opinions are based, it must be disclosed to the other side in the testifying expert’s report and can be discovered further during the testifying expert’s deposition. The expert consultant may even be deposed. When retaining a true, behind the scene consultant, though, all that really matters are the consultant’s expertise, availability, and ability to work as part of a team.

So, what should you look for in a testifying expert? As with a consulting expert, expertise and availability are paramount. The testifying expert’s ability to work as part of a team is important as well. A host of additional considerations come into play, however, when selecting a testifying expert. Most of these considerations concern how the fact finder at trial, which in patent infringement cases increasingly has become juries, will perceive the expert. Surveys suggest that juries prefer experts who have published in professional journals to those who have not. They prefer experts who testify rarely, as opposed to hired guns who appear, more than anything else, to be in the expert witness business. I once had the pleasure of concluding the introduction of an expert at trial with the question: "have you ever before been retained as an expert in a legal matter or given expert testimony at deposition or trial?" Of course, I knew that the answer to my question was "no" but what I didn’t expect was that the expert went to add "but I have to tell you, I’m looking forward to it." Everybody in the room chuckled, and our client won the case. Juries tend to prefer older expert witnesses to younger ones, but appear to make little distinction between male and female experts. Academic scientists are perceived as both trustworthy and knowledgeable. Lawyers, while recognized as knowledgeable, are not perceived as trustworthy. Some surveys suggest that government workers are perceived as neither. Real world experience with the subject matter of the expert’s testimony is critical. While surveys suggest that juries prefer experts who are not being compensated for their time, it is not usually realistic to think you will find an expert willing to testify for free; at least not one you would want.

In addition, testifying experts need to be articulate and understandable. An expert who looks and sounds impressive, but whom nobody understands, is not helping your case. Jargon is bad. So, in addition to being able simply to speak clearly, a testifying expert must be an effective teacher who understands the audience (the jury, the judge, and the appellate court) and can explain challenging scientific, economic, or legal concepts in a thoughtful and persuasive manner that those audiences can understand. In addition to doing my best to impress this issue upon my testifying experts during their preparation, I work hard to be especially mindful of it during their actual testimony. When the expert slips into techno-speak, as in my experience they inevitably do, I try to diffuse the situation with questions like: "Dr. So and So, for those of us who barely passed biology in high school, could you please explain that in simpler terms?" The last thing I want is for the jury to misunderstand a concept I thought important enough to address at trial, or worse, to feel like everybody in the courtroom understands a concept that they don’t.

As the technology around us becomes more mind-bogglingly complex, so too does the patent litigation it spawns. Each week, the United States Patent and Trademark Office and patent offices all over the world issue patents covering all manner of technology that ordinary people can neither pronounce nor understand. We ask these people, as judges, jurors, and lawyers, to resolve incredibly dense disputes involving these patents, and they look to experts to help them do so. Patent owners and accused infringers face few decisions, therefore, as critical to the outcome of their case as the experts they choose to rely upon.

(A different version of this article appeared in the August 2004 issue of the American Lawyer’s IP Law & Business publication.)