The involvement of a medical expert witness in medical cases can take different forms. The expert witness may be asked to evaluate the merits of a claim before legal action is filed. The expert witness may be tasked to review the medical records, provide a written opinion regarding the standard of care and any deviation from the standard of care. If the case continues, during deposition, the expert will most likely provide recorded testimony, under oath, answer questions of attorneys from both sides. If the case continues to court, the expert witness will be required to provide testimony, under oath, to the judge or jury.