On April 28, around noon, according to one report, Mr. Gennady Kernes, mayor of the eastern Ukraine city of Kharkiv, went for a cross-training jog in a city park. En route, an assassin shot the mayor in the back. According to his bodyguards, a sniper fired at Kernes from long range. Hitting the back of a running man at a distance -- the upper body mass, to use the lingo -- indicates a crack sniper fired the shot. But even at close range, a running man can be a tough target. Bullet to the head, bullet to the heart --...