Great question. First this is a legal matter and the specifics of the case need to be handled through legal channels. I would not discuss the issue with the Soldier.
It is important the Soldier understand they will be treated fairly and that you will be a responsible leader and ensure they receive due process and fair treatment. By treating the Soldier fairly, the Soldier will usually do his/her best with regard to duty performance. If the Soldier is ostracized then other events are more likely. The Soldier can feel isolated, unwanted, become depressed, etc. Therefore it is important to keep the Soldier as part of the team. He may have done something wrong but it is not your position to punish him.
In my opinion your position is to let him know you will support him as you are required by duty, and that he has the capability to recover from this event. This is not a life ending event, but a life changing event. Even a bad situation like this can be used to put a person on the right track. If convicted, the Soldier will most likely be separated. If it is going in that direction the Soldier needs to do their best to begin preparing for the civilian sector. They can best do that by keeping the chain of command on their side by maintaining a positive and professional attitude. The chain of command can assist the Soldier in transition by allowing them to research benefits that might be available to them; perhaps assistance in preparing a resume, possible civilian careers, etc.