The Washington Post got some great quotes from capital defense lawyers in this article on opening statements in the Sniper case trial that will be heard today.

Death penalty trials are as grueling as it gets for lawyers. The initial statements are the first public glimpse of months of behind-the-scenes preparation, so intense that attorneys often turn their neighbors and relatives into sounding boards, alter their diets and forgo sleep. In the days before openings, some attorneys cut themselves off from the world as they prepare. Others wake up in the middle of the night, their hearts racing.

As a defense attorney, it's like being the producer, director and conductor for an opera that will run one night, and if the critics don't like the show they are going to kill your leading man," said South Carolina lawyer David Bruck, a veteran of high-profile capital cases.

Translation: First impressions count. Opening arguments are the first chance the lawyers have to present their case, using themes and theories they will raise again and again throughout the trial. They are often presented using a story-telling format.

Opening arguments are very important. Studies show that 75% of the time the final result in a trial is the same as the tentative conclusion held at the end of opening statement. Utilizing theme and theory, the opening statement is like a preview of coming attractions. It frames the issues, focuses the case, and tells the story in a powerful way that will make the rest of the case highly persuasive.