In many trials, particularly those that involve complex medical or scientific evidence, parties will hire expert witnesses to testify. Expert witnesses are professionals who are deemed by the court to have “expert” experience in a particular field. Some expert witnesses only rarely appear in court, but most are professional experts, which is to say that the majority of their income comes not through the practice of their profession, but through testimony and appearance fees. There are whole networks of experts willing to testify in trials. The process of choosing one is known as “expert shopping.”
Expert shopping begins with an identification of the type of expert witness that is needed. The main goal in having an expert witness testify is to allow the court to hear a professional opinion on the facts. Expert witnesses are common in medical malpractice cases and product liability cases, where the facts are so complicated and nuanced that a judge or jury could not be expected to understand them independently. Some experts present on non-scientific topics like politics, news media, or standard business practices, usually in cases where something has gone wrong. The expert’s job is to identify what is common and generally accepted in the industry.
The next step in expert shopping is an evaluation of the available experts’ credentials. Both sides in lawsuits, the prosecution and the defense, are permitted to question any expert witness who testifies. It is therefore important that the expert who is ultimately selected is truly knowledgeable. An expert whose professional experience or credibility is debunked by the opposition is not generally effective.
Lawyers who are engaging in expert shopping usually have several tactics for choosing a witness. They may begin by evaluating witnesses’ professional backgrounds, looking for length of time on the job and accolades won. Training and education are also important. Because part of an expert’s job is to credibly present evidence, demeanor and professionalism are often important things lawyers look for, too.
Expert shopping often involves interviews, sample questions, and price negotiations. In very high-profile cases, test screenings and mock trials are sometimes part of the expert shopping process. Prospective experts will be presented to a panel of test subjects brought in by a law firm, and the expert with the highest scores on presentation and ability to provide convincing testimony are likely to be the ones hired.
Expert shopping is an accepted part of the expert witness selection process. Expert witnesses are permitted under the evidence laws of most trial systems around the world, but this does not mean that the practice is without its opponents. While experts can serve an important educational role, the commercialization of the expert selection and payment process has led to a significant body of criticism. Experts who derive the bulk of their income from witness fees are typically the most controversial.