Why do police ask for your religion?

I was arrested for sitting on a park bench on October 30th and they asked what religion I was.

I don't see how that's relative to anything at all, even a hate crime, seeing as what religion you are is irrelevant to your actions within your crime.

Isn't there something where like Muslims are not to be arrested during Ramadan or something like that?

I doubt that would have any relevance to this situation, but yeah.