Don't want to get into a pissing match here, but I think civilian authorities can do just that. If the crime occurred off base, the suspect is subject to double jeopardy. It's one of the catch-22s found in military law. Well, that usually applies to lower enlisted ranks. If you've spent some time in and the command has invested money and training into you, they won't throw you under the bus as quickly. Politics, favoritism, cronyism and tenure are an offender's best hope against prosecution in the military.