The manslaughter trial of Conrad Murray for the death of Singer Michael Jackson illustrated the huge difference between the law governing opening statements and closing arguments in both criminal and civil trials. Every lawyer wants to gain an early advantage by persuading the jury in opening statements by argument about what the anticipated testimony must mean (in that attorney's client's favor, of course), but for fairness, the law requires that the lawyers making opening statements give to the jurors only an outline of the evidence they expect to present during the trial. That means a factual roadmap of how the trial will unfold. The goal of the rules is to help the jury focus on the relevant testimony.
If you've attended a trial, you know that efforts are made by both sides to argue the case in opening by using the phrase "the evidence will show" followed by a diatribe that is expected to persuade jurors to their view. "The evidence will show" phrase is designed to obscure the argumentative nature of the next statement or two that the lawyer will make. Such is life in the courtroom. To the contrary, in closing argument (note that I said "argument") every possible inference from the evidence in the case can be argued. Commentary is permitted, even required, to do justice to the client's case.
In Conrad Murray's trial, you saw drama generated by the emotion of the closing arguments. In their closings, the lawyers were passionate, persuasive actors advocating their positions. That was the only time the rules of trial permitted them to argue to the jury their clients' version of the events. Conrad Murray's fate, similar to the fate of many a criminal defendant, rode on the effectiveness of those arguments.
