The videocamera, long the weapon of choice among obsessive parents, is finding favor with crime fighters these days. The Los Angeles police's grisly beating of Rodney King, videotaped by an amateur and aired on national television in March, was only the first of a growing number of America's Unfunniest Home Videos. At a Washington trial last month, prosecutors introduced a videotape of five men robbing and beating victims during a 1989 crime spree, which was recorded for posterity by one of the defendants.
Last week, during a fireworks display in Detroit, an amateur photographer videotaped a gang of young black women...