Civilians occasionally find themselves in harm's way when officers use deadly force, though usually only a handful of times annually. When that happens, a rigid process of investigation is set in motion — and the police department can reasonably expect a lawsuit. The latest episode came when police say a man disgruntled over losing his job a year ago shot a former colleague to death and pointed his weapon at two police officers in the shadow of a major tourist attraction. He apparently wasn't able to fire before police killed him, one firing off seven rounds and the other nine. Bystanders...