What's the Charge?

I'm in Texas. My son was in an altercation with someone who pulled in front of him with their car, stopped, got out and approached him yelling and waving his arms around that my son had cut him off. My son hit him first,two or three times in the jaw, because he thought the guy was going to hit him. When the bailbond's man called he said my son was charged with aggravated assault. My son had a knife in his pocket, legal size, but did not pull it out at all. He also had one tablet of hydrocodone. When we called the jail they said the charge was possesion of a controlled substance. Why are we being told two different charges? Or is he being charged with both? The hydrocodone was a prescription he had received for pain and we have the prescription bottle. Also, the police gave him back the knife. The bond was $1,500 and we paid the bailbond's man $150. Any information would be great. Thank you.

He may well be charged with more than one offense. The quickest ways to try to find out are probably these: His bail bondsman may know all the charges he is facing, he can hire a criminal defense lawyer (or seek appointed counsel) and have his lawyer explain, or he can try to find out from his court file.