Got a case going to trial tomorrow in which we have venue based on the fact that juvenile resides in our county and is on probation in our county despite fact that offense was committed in another county. How do you all typically prove up venue? I can certainly do it through his p.o. but i suspect that would raise an objection.

Is mom or dad on your witness list ?
If so, tell defense that you are going to call one or both or they can stip to it.
I generally put parent or guardian on wit list because I may need them to prove up DOB which is a jurisdictional issue.

I bet you can do it through the po too without objection. Most pos have the "client" fill out some paperwork and it will generally have their address and they have done interviews with client where he has stated where he lives or maybe if you are lucky have done a home visit.