CHICAGO – Back in the early ’70s, as a cub working off the overnight city desk at the Chicago Tribune, you learned fast that all murders were not equal. Sure, all were listed methodically on the deputy superintendent’s logbook at the old police headquarters at 11th and State streets. But while killings on the city’s predominantly white North Side were almost always pursued by our small band of nocturnal newsmen, the more numerous homicides in the black neighborhoods of the South and West Sides most often were ignored. There was even a winking code word for the latter category. They were “blue.” Blue, as in “cheap domestic,” where a drunken live-in boyfriend kills his common-law mate. Blue, as in someone shot in the face after a street-corner dice game gone awry. Judging by how the other four daily newspapers (yes, four!) covered and displayed their homicides, it’s safe to assume the same double standard applied.