I know this is a legal term like DUI, but What is a D.U.E.?

I was watching Judge Judy, and she asked the plaintiff what she had been arrested for. The plaintiff said d.u.e., and judge judy said, you can't get arrested for d.u.e. in new york. Then the plaintiff said that she was arrested because she had 2 d.u.e.'s. What is a d.u.e? I can't find it anywhere on the net.