Expert witnesses play an important role in trials. An expert witness or professional witness is an individual who testifies in a court case to help explain technical, scientific or medical matters. The witness is classified as an 'expert' because he/she possesses specialized knowledge about matters involved in the lawsuit.
The expert witness may work for the court or for either side of the prosecution and his/her experience and testimony may be challenged. The expert witness is expected to be an independent party with no stake in the proceedings.
The role of the expert witness in a trial is to use his/her education and experience -- which is reviewed by the judge to determine his qualifications -- to provide both an opinion based on his/her education and experience as to the interpretation of the facts and also to attempt to explain the basis of that interpretation to the finder of fact - either the jury or judge -- so that the factfinder can make a reasonable finding based on the facts.
There is a legal standard that must be satisfied. The test is "helpfulness." Under the Federal Rules of Evidence, an expert testifying in federal court must satisfy the requirements of Rule 702. Generally, under that rule, an expert is a person with "scientific, technical, or other specialized knowledge" who can "assist the trier of fact" to determine a disputed fact.
Expert witnesses are often used in lawsuits where important issues in the case depend on understanding evidence that is commonly outside the judge or juries' knowledge. For example, experts are often used in cases dealing with medical malpractice and toxic torts because those cases call for the introduction of evidence that stems from terminology, specialized knowledge and mathematical or scientific analyses not ordinarily known by the judge and jury hearing the case. And, in more and more cases, computer experts are testifying because, while many of us are familiar with the use of computers for word processing and email communications, few people are familiar with how computer information is stored, destroyed or retrieved.
In medical malpractice cases, expert witnesses help to establish the medical standard of care that applied to the lawsuit. They do this by describing the relevant standard of care, identify whether that standard of medical care was not followed and then give an opinion as to whether that breach caused the injury.
Expert witnesses can't say just anything in court. An expert is allowed to testify in the form of opinion so long as the testimony is based upon sufficient facts or data, is the product of reliable principles and methods and the expert witness has applied the principles and methods reliably to the facts of the case.
Maryland uses a "general acceptance" rule for scientific evidence and expert scientific testimony. The "general acceptance" rule was adopted by Maryland's courts in 1978 in Reed v. Stone, 283 Md. 374. That rule came from a case, Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), where a District of Columbia federal appellate court reviewed the notion of general acceptance and held that "the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs."
However, many courts use a different standard -- the "Daubert standard" -- to determine the admissibility of expert scientific testimony. Under Daubert, the judge determines whether expert testimony is relevant and is a based on a reliable foundation so as to be admitted into testimony.
It's important to note that expert opinions, particularly in new or cutting edge areas of science and medicine, are frequently challenged. There is a lag time between the science and the law, with the law lagging behind the science in terms of evidence by years in some cases.
There has been criticism of experts who allegedly make their living by testifying in court cases. Courts are taking stronger stances against these so-called "questionable" experts. For example, courts in Arizona and Maryland in 2009 upheld state restrictions against expert witnesses. Maryland requires that doctors spend a certain amount of time actively practicing medicine. In University of Maryland Medical System Corp. v. Rebecca Marie Waldt, the Court of Appeals of Maryland - the state's top court -- ruled that Maryland's expert witness regulations were constitutional. The law prohibits the use of medical experts who devote more than 20% of their professional time to testifying in personal injury cases. At least 30 states have similar expert witness laws.
Baltimore, Md.-based Belsky, Weinberg & Horowitz has been fighting for the victims of negligence for many years. Call us at 410-234-0100 or email us for a free consultation and let us help you.