Most schools require at least one (sometimes two) academic refs. And especially since you went to grad school, one would assume that you have several very good professor contacts, or at least your supervisor, from that experience who could write good recs. Law schools might actually be suspicious of the fact that you went to grad school and don't have someone there you can get a rec from.
EDIT: Oh wow, sorry, didn't know this thread had been dead for months. I saw the new post today and assumed it was a recent thread. Sorry to extend this farther.