@rtc143 I still feel there is too much overlap with Flint in terms of what job they have.
@Dark Angel I have issues with the Icelandic demons thing as it's very vague and doesn't really relate to anything vaguely demonic in myth or practice. Demons aren't really a part of Norse myth in the sense I also don't think full demons are running around the earth; they're leashed. Also, no real relationship between abilities and background or any sense of where she'd learn to use a firearm or become a competent assassin.
Beyond that guys, the job of the Courts isn't to enforce mortal law; they are there to make sure that secrecy is upheld and that one rogue element doesn't endanger everyone. They're far more interested in people writing books and who might be consulting with Hollywood than worrying about crime as mortal authorities do. They certainly don't give a fuck about mortal investigations unless it finds a trail, and then the job is generally to clean up that trail and set up plausible deniability while admonishing the person that is exposing them unnecessarily.
Edit: Of course, plenty of nobles within the system with powers in the courts view the courts as a great way to farm the tithes for their own lavish comfort. Also, the system is based on inheritance, mostly because it was set up in the Middle Ages.