In the second season of the BBC's hit show "Sherlock," shadowy snipers threaten the eponymous detective's friends by skulking around stairwells with high-powered rifles or infiltrating their homes and workplaces. In real life, targets of assassination in Britain are more likely to be killed while walking their dogs or going shopping, new research finds. The study of contract killings spanning from 1974 to 2013, published in The Howard Journal of Criminal Justice, finds that assassinations are often rather mundane. "Hit men are familiar figures in films and video games, carrying out 'hits' in underworld bars or from the rooftops with...