The shooting was Chicago-style, but the setting was Moscow. A cop surprised four masked burglars trying to break into a store. There was a burst of gunfire, and the four leaped into a taxi and fled, leaving the policeman dying from seven bullet wounds. Eyewitnesses provided one useful clue: the gunmen wore the narrow trousers, oversized jackets and ducktail haircuts of stilyagi, the Russian version of zoot-suiters.
Police grabbed Viktor Shashkin, 19, an awkward, gangling youth with big, vacant eyes; Vadim Vorobiev, 17, with a dangling forelock and a crooked smile that revealed a gold cap set on a healthy tooth—a...