I would be VERY careful about picking a law school based on its dual-degree program. The reputation of the school is the number one factor in getting your first legal job. That should be your first priority. If that school has a dual-degree program, great. If not, then maybe you can get a MSW later. But if you ever intend to practice law, only seriously consider reputable schools. And if you don't intend to practice law, why get the dual degree.
Obviously, I'm a weird person for saying all this, but I'm basing this off my personal experience with pursuing the degrees separately because I know how valuable the ranking of your school is in the legal market.