Why the secrecy? What's the big deal if the prosecutor sees the motion? Well, a couple of reasons. One, in many cases it may reveal the client's defense strategy. But second, consider this hypothetical. The State has an expert who is new and inexperienced but thinks your client's fingerprint was found at a crime scene. You decide to consult a very seasoned, very experienced fingerprint examiner. Your examiner agrees with the State's expert. In most cases, the State will never know this. But if the State knows who your consulting expert is, the prosecutor can depose your expert to see what the expert found. And now the State can use your own consulting expert against you. The State's case just became stronger.