Although the examinations are complete the case is still only partially finished. The next big step is to present the findings of his or her examinations in a court of law. Expert testimony is commonplace in almost every criminal trial. Expert testimony is that given by a specialist who has been recognized by the court as having expert knowledge about evidence in the case.
Ordinary testimony is restricted to statements concerning what the witness actually saw or heard.
An ordinary witness is prohibited from stating opinions about the case and from quoting statements made by other people. In contrast, an expert witness is allowed to express an opinion about the validity of the evidence in a case and may quote the statements of other experts in support of an opinion. T he first step in testifying usually involves stating your name, job description, and where you are employed. I normally explain to the jury what firearms identification is and will tell them a little about our lab system. Next, I will attempt to be recognized or qualified as an expert by the court.