Not to say that I don't READ these stories (I read badfic all the time. And horriblefic! And mediocrefic and goodfic, and all things between), but there's absolutely no way in the universe to make me BUY one where someone's secretly a magical creature: the best writing in the world would still result in "A well-written take on an appallingly stupid premise". Save it for a fandom that's compatible with magical realism, which many fandoms are, but most criminal procedural dramas have a very definite non-supernatural worldview that's easily observable in canon. If canon leaves the door open to the supernatural - say, Grey's Anatomy, where we saw a near-death experience onscreen - then yes, bring it on. CSI? Absolutely not, not without a complete AU that makes the divergence clear all over.