Short of a racist statement you probably can't tell if someone is racist (judge or not). Mitigating factors of each of his or her past cases would make proof very difficult unless there that particular judge's ruling were well outside standard deviations as compared to the rulings of all local judges in the area for similar cases. This data would be extraordinarily difficult to compile, and most attorneys who would potentially argue in front of the judge would never want to make that charge.
That said, it is highly likely that the judge is not racists. To be clear, his or her experience may bias their decision making to some degree, but if you stand before the court, you should be able to easily move things in your favor. Dress well, speak well, be respectful, and be restrained in your speech and demeanor, and you will be fine.