That leads to two fundamental principles that, I believe, should be true of all opening statements. I have already addressed the first: You must deliver on your promises. The second is that you must deal effectively with the best evidence against you. That is often a difficult thing to do. It may be that less is more, and that the best course is to say nothing. But that can be very risky. It is usually better to put the evidence into the context in which you want the jury to consider and then discount it. In either event, what you say—or don’t say—about the other side’s evidence matters a lot.
Lang's most seminal film was M (1931, Germ.) - his first sound feature (bridging the gap between silents and talkies). It was an expressionistic psychological thriller about a child molester serial killer. The pedophile-psychopath was identified as Hans Beckert (Peter Lorre) - his coat back was marked in chalk with the letter "M." He was caught hiding in an attic, and taken to a large abandoned brewery building to stand trial, where he was questioned by a panel of underworld boss-leaders.