Throughout the trial, Roosevelt's decision of creating a military tribunal to prosecute the Germans was challenged by Lieutenant Colonel Kenneth Royall, who was appointed to defend the Germans. Royall said that Roosevelt had no right to create a military tribunal to try his clients, citing "Ex parte Milligan" (1866), a case in which the U.S. Supreme Court ruled that the federal government could not establish military tribunals to try civilians in areas where civilian courts were functioning, even during wartime. Since civilian courts were functioning in Washington D.C., he argued that the case involving the Germans should be heard there. Attorney General Francis Biddle, who was appointed as a prosecutor of the case, responded that the clients who, acting on behalf of the German government, secretly entered into U.S. territory without proper uniforms in time of war for the purpose of committing hostile acts, were not entitled to have access to civilian courts. Biddle stated that, "This is not a trial of offenses of law of the civil courts, but is a trial of the offenses of the law of war, which is not recognizable by the civil courts. It is the trial, as alleged in the charges, of certain enemies who crossed our borders ... and who crossed in disguise and landed here ... They are exactly and precisely in the same position as armed forces invading this country."