The forensic scientists must deal with lawyers who may attempt to reinterpret physical science data. Therefore, forensic scientists must present the result of their findings in a clear, concise, and complete fashion so as to minimize ambiguity and misinterpretation in the courtroom. Four areas are considered: (1) the question of the 'expert witness,' (2) the difference between 'scientific truth' and 'legal truth,' (3) the conflicts between the forensic scientists and lawyers, and (4) the importance of testimony relating to physical evidence in obtaining a verdict. The early history of the forensic sciences is traced, and precedents in forensic science testimony are discussed, including the cases of Frye v. United States and State v. Barber. The article contends that only by becoming aware of the rules of the social institution of the courtroom will forensic sciences reach their full potential for growth and development. Twelve references are provided.