A trial lawyer without a theme is a warrior without a weapon. Themes or motifs (think Beethoven’s Fifth Symphony) are short, pithy statements, usually one sentence long, which most embodies what the story is about. A typical theme: “This is a case about greed and how far these corporate criminals were willing to go to steal huge amounts of money.” Even better is the theme Johnnie Cochran used in the O.J. Simpson summation, “If it doesn’t fit, you must acquit.” A theme is a unifying idea that is a recurrent element in your story. (How much impact did Cochran’s defense have on Los Angeles? After his death they named a middle school after him.) When you are creating the theme, anticipate what the juror’s task is at the end of the case and create a phrase that encompasses what you want the decision makers to do with your case. Questions, images and exhibits enhance your theme. Hammer the theme throughout the trial

A good article explaining themes.