You do not specify your service, but each service (Army/Navy/Air Force/Marines) have published guidelines that are to be looked at in the absence of a court order. If there is a court order that will take precedence.
Thanks for the chance to help You son should file a personal claim for the value of the computer with the US government. Tell him to head to legal assistance on base and tell them what happened and that he wants to file a claim for the cost of the computer. There is a process in place that will allow him to recover most if not all of the money. If I recall correctly its called the Personal Claims Act (PCA) Good luck