Although this is classified as a "blaxploitation" film, it manages to be much more race-baiting than usual by having a white sniper (obviously modeled after Scorpio from "Dirty Harry" and thus indirectly modeled after the real-life Zodiac Killer)who disguises himself in black-face as he commits incendiary crimes against middle-class whites (which his why he is called "the zebra killer"--not because he kills any zebras). The good guy cop meanwhile is a black guy, thus giving the title its blaxploitation credentials. Still the plot was apparently pretty controversial which is no doubt why this film is pretty hard to find today even though it is probably cult director William "Grizzly" Girdler's best film.
It is obviously the kind of film that couldn't be made today, and that alone in my book makes it worth a look. Unfortunately, the version I saw looked awful suffering from both bad original film elements and tracking problems from one of the few remaining videotapes that is still circulating around. I'd like to see this film resurrected on DVD. Fat chance though probably since many of Girdler's early films (like the vastly inferior, but much less controversial "Three on a Meathook")have yet to see the light of a DVD player. Still they released the even more racially-insensitive "Fight for Your Live" (although that film had the advantage of actually having been banned in Britain)so maybe there is hope.