Last Sunday in Las Vegas, Stephen Paddock turned his guns on a country music concert, killing 59, including himself, and wounding more than 500. The mass murder was beyond horrific, an act of pure evil as President Trump said, but it easily could have been worse in several ways.
Stephen Paddock was a mystery man who kept to himself. Suppose he had emblazoned something like "Murder, Inc." on his business card, an open warning of deadly intentions.
That was the practice of Nidal Malik Hasan, a U.S. Army major who openly billed himself as a "Soldier of Allah." If that is not a warning, it is hard to imagine what one would look like.