He's facing a felony charge that has the potetial of putting him in prison. Step one is to hire a criminal defense attorney. His second issue is an immigration issue, so he'll need to hire an immigration attorney. My last suggestion is to come off that bond you posted in the meanwhile so he can accumulate credit for the time he is serving in jail for the criminal charges.
There are two issues that need to be addressed. As to the immigration question, get all of the documentation together establishing his legal status and the naturalization of his mother, and consult with a lawyer specializing in immigration law. Determine from the immigration lawyer what the problem is at this point that resulted in the ICE hold, and what the result will be in regards to immigration if he were convicted of the charges he is charged with. As to the criminal charge, get him representation by an experienced criminal defense lawyer licensed to practice law in FL as soon as possible. Each of these can take on a life of their own, and the criminal case disposition could, depending on how it is resolved, have an impact on the immigration problem. Good luck.
This information is offered for informational purposes only, as I do not practice law in your State. It is not intended as legal advice and you should not rely upon it to decide how to resolve this issue. No Attorney-Client relationship is intended or established by this response. You are faced with a situation where you need to consult with an experienced defense lawyer admitted to practice law in your State before you make any decisions as to how to resolve this issue.