The commanding officer of a Marine Corps or Navy unit may order personnel under their command to be arrested by a Master-At-Arms for committing a minor offense punishable by a Captain's Mast. However they cannot order NCIS agents to arrest a sailor for a court-martial level offense, for one NCIS exists outside the military chain of command, NCIS and its director answer directly to the Secretary of the Navy. Second it is up to the Judge Advocate General's (JAG) office to determine if there is cause to arrest someone and initiate an Article 11 hearing, which is to determine if there is sufficient evidence to warrant a court-martial.