Now that you mention it, is it even allowed that someone outside the DAs office try criminal cases? The DA is the legal representative of the state in that case, and I don't know if someone else can just step in there.
The concept of "private prosecution" exists, but my understanding is that it's not usually practiced (anymore). Some states prohibit it completely, and of those that do allow it some judicial authority is still usually required to sign off on it before it can proceed.
