The problem is that a jury won’t convict an owner usually for this kind of thing, and also, in many cases the owner really did have little warning that the animal was dangerous. I do think that prohibiting the breed is something that should be considered. We don’t let people keep tigers or wolves. Granted that pit bulls are not tigers or wolves, but they are quite dangerous nevertheless. People who like pit bulls should just get used to liking a different breed. There are plenty to choose from.
They won't convict if the owner is never charged which seems to be the pattern. They should be charged and brought to trial every time. If they get off, then they get off, but I suspect that someone whoe dogs mauled a person and was facing 5 years in prison even if he/she wasn't found guilty would think twice about owning that sort of dog again, and it might just put a damper on other vicious dog lovers as well
Read the link to the pdf file about how pit bulls are far and away the worst about injuries. I would think that just the fact of ownership of a pit bull would be enough to legally say that the owner knew the dog was dangerous.
Owners should be held responsible, always.