During a court hearing or trial, witnesses are called to present testimony. Although most witnesses are lay people with relevant knowledge to share with the court, a court expert witness is different. The expert witness is someone who is called by the court or one of the parties involved to provide testimony to assist the court in ruling on an issue that is not obvious or common knowledge to a layperson. A court expert witness is hired and paid by one of the people related to the matter being considered by the court, and therefore must show expertise to the court's satisfaction before being designated as such.
These types of witnesses are called in many different types of cases for a variety of reasons. In a divorce, an expert witness is often called to clarify the value of property, or to provide expert witness testimony as to the best option for child custody based on home studies or psychological evaluations. During personal injury cases, expert witnesses are called to testify as to the past, present, or future medical condition or prognosis of an injured person. Expert witnesses can also provide witness testimony as to the likelihood of a sick or injured party being able to obtain and maintain gainful employment, the value of past and future lost wages, or potential cost of future medical bills. In criminal cases, forensic experts are often called to offer the court and jury translation and application of technical and scientific data related to evidence that may not be easily analyzed or understood by the layperson.
In most cases, a court expert witness is employed by one party or the other and is paid by that party. Despite this fact, the expert's testimony is supposed to be unbiased, researched, and documented. The expert witness not only answers questions from the attorney that hired him or her, but also must be able to stand up to cross-examination. For this reason, an expert generally submits a curriculum vitae, or resume, that details all training, education, skills, experience, publications, and prior testimony for the attorneys and the judge to review before approving the person as a court expert witness. The opposing party has the opportunity to provide court expert witness testimony from their own expert that contradicts the witness testimony given by the first court expert witness, assuming there is an expert that disagrees with the first findings.
Because a great deal of research and preparation goes into being an expert witness, most any court expert witness charges a steep fee. With the cost of hiring an expert witness being high, most court expert witness testimony is reserved for cases in which something of great value is at stake. It is unlikely that a small claims court case will include expert witness testimony, because the cost of doing so would likely be higher than any recovery. In cases of divorce or probate where there is a large estate to split, court expert witnesses are more likely to testify. When a criminal case involves rape or murder, there is more than money at stake; for this reason, it is not uncommon to hear expert testimony offered by the prosecution to explain how evidence was collected and analyzed, or by the defense to explain how the process was tainted or not scientifically proven.
In years past, it was more difficult and expensive to find an expert witness, but finding one has been made simpler through the use of computers. By utilizing Internet legal websites that offer databases of expert witnesses on virtually any topic, an attorney can browse experts by field, experience, and client rating. A trip to the legal library of the local courthouse or spending time using a search engine can provide even an inexperienced layperson a list of potential experts for virtually any case.