Testimony is a form of evidence that is presented to a judge or jury by a witness. Usually, the witness is under oath to tell the truth. Witnesses may be called upon to describe the character of a person they know, or they may have some direct connection to the case. For example, suppose that a case is filed against a driver for causing a car accident as a result of negligent driving. At trial, a person who saw the accident may be called to testify about what he or she witnessed.
Typically, court testimony is presented orally by a witness. In some cases, however, it may be presented in writing through a signed statement. For example, a deposition or an affidavit may be entered into evidence in lieu of oral testimony in some circumstances.
Witnesses may present trial testimony voluntarily, or they may be ordered to testify by a court. This type of court order is usually called a subpoena, and it typically informs the witness when and where he or she is required to testify. Witnesses who fail to comply with subpoenas may be sanctioned by courts. Subpoenaed witnesses frequently receive payment for their time and reimbursement for transportation expenses.
In order to present testimony, a witness must be found competent to stand trial. By and large, this means that the witness must be able to communicate at trial. In addition, the witness must understand that he or she has a duty to tell the truth. Witnesses who are found incompetent generally cannot testify. For example, a young child or a person with a severe mental disability may be found incompetent to present testimony in a lawsuit.
In most cases, testimonies can be elicited from either lay witnesses or expert witnesses. In general, there are limits on what lay witnesses can testify about. Usually, they are limited to testifying about events, evidence, or facts that they have personal knowledge about. Most lay witnesses are not allowed to give their opinions about a case.
Expert witness testimony, on the other hand, is broader in scope, and it can be given by a witness who has specialized knowledge about a subject pertaining to the case. Unlike lay witnesses, qualified expert witnesses are frequently allowed to present opinion testimony. Usually, a trial attorney must qualify the expert by showing that he or she possesses superior training, education, skills, and knowledge about a particular subject. If properly qualified, the expert can deliver his or her opinion about an issue in the case in order to assist in reaching a decision.