Have a certification hearing coming up next week on a murder. Have a confession that will NOT be admissible in the trial (magistrate warning was not part of recording, although warnings were done in writing). I plan on admitting it at the certification - case law seems to support my ability to do this. I also do not plan on putting on much other evidence regarding the crime itself. I am doing this for two reasons. First, we have a mother who has been a great impediment to a plea. She plain thinks her son didn't do it. I think it would furhter the plea process for her to hear her son's audio statement saying he killed this kid. Second, I would rather the other side see as little of my hand as possible. Does anyone see any problems with this?

If the Judge doesn't agree with you (and I'm not sure I do) that the confession is admissible and the other side has not seen any other documents you have 24 hours before your hearing and you have no other witness waiting in the wings, you are dead in the water.

Other side has seen everything that we have. All required documents have been sent to the Court well within the time constraints. We will have witnesses available as "backup". Essentially, my question (although apparently not very well stated) was, does anyone see a problem with offering only the confession if it's admitted? I would rather not make all of my witnesses available for defense counsel twice.

Sorry that I misunderstood.
And, the only "issue" I see may still be a misunderstanding of how you are going to put on the confession.

The only way I have put in a non sponsered confession is during a waiver of cert hearing.
If you are just offering the confession as a document without a witness, then you will have an ID issue. If you are planning on putting on the officer that took the confession, I think you are fine and thats what I usually do if I am so lucky to have a confession. Of course, then you open your officer up to a fishing expedition by the defense on cross.

If I have just totally misunderstood this whole post, chalk it up to living temporarily in an RV with 2 children under 4