Yes, there are frum Jews in top law schools. Their backgrounds vary. Some have yeshiva degrees. Some have Touro degrees. Some have online degrees. Some even have degrees from real schools like Queens College or Brooklyn College. It’s probably worth pointing out that outside of the frum community, it is not common for people to go from Touro or even Brooklyn College to a top law school. Most people at top law schools went to top undergrads as well.
Grades-wise, my perception is that there is no trend among frum students at law school. We’ve discussed the rumored Fordham study, and a friend even tried to get hold of it. Nothing I’ve seen leads me to think there is any truth to it though. The frum students I know might trend slightly higher than average, but that is mainly because I don’t know anyone who was at the very bottom of their class.
Actually come to think of it I just remembered that the top graduate at Harvard a few years back was a frum guy. He went on to be a Supreme Court clerk and is now at a big firm. He worked on the metzitza b’peh case pro bono. Poor guy – they never had a chance.