There's also the issue of what really is a "Pit Bull".
Although fatal attacks on humans appear to be a breed-specific problem (pit bull-type dogs and Rottweilers), other breeds may bite and cause fatalities at higher rates. Because of difficulties inherent in determining a dog’s breed with certainty, enforcement of breed-specific ordinances raises con- stitutional and practical issues. Fatal attacks represent a small proportion of dog bite injuries to humans and, therefore, should not be the primary factor driving public policy concerning dangerous dogs. Many practi- cal alternatives to breed-specific ordinances exist and hold promise for prevention of dog bites. (J Am Vet Med Assoc 2000;217:836–840)