I agree with learned MO counsel and wish to add the following. If he has not been taken into custody on the capias et I would highly recommend talking with local counsel immediately to see if arrangements could be made quickly so your son could turn himself in with the assistance of counsel.
To be more precise, a capias bond is a bond where you have no ability to post bond. You have to ask the judge to set a bond or otherwise release you. An attorney will get a bond set or try to get your release on your own recognizance.
NEVER describe your facts in an online forum. I have CONFIRMED there is at least ONE county prosecutor that is a member of this site.
My statements are my opinion solely based on the information provided, and that opinion can be wrong if your facts are different than what I believed them to be. If you have any further questions, you can contact me at 636-532-1400 or through my website http://mcmichael-logan.com