Permission for a Witness to Explain His or Her Testimony

Permission for a witness to explain his or her testimony by visual illustration, such as a diagram or map:

A) rests within the discretion of the trial judge.
B) will not be given by the judge because the introduction of the illustration (map or diagram) is not competent evidence and prejudicial to the accused.
C) is usually refused because this is equivalent to using a map or plat to establish a particular fact.
D) is generally approved; however, the use of a blackboard to illustrate testimony in a criminal case may not be permitted.