<P> Unlike a civilian trial, the convening authority's "command prerogative" entitles them to amend or overturn the sentence of a court - martial . However, the convening authority may not set aside a finding of not guilty or increase the severity of a recommended punishment . </P> <P> While normally only exercised in practice by members of the armed forces, six civilian officials can also act as a convening authority: the President, the Secretary of Defense, the three "service secretaries" (the Secretary of the Army, Secretary of the Navy, and Secretary of the Air Force), and the Secretary of Homeland Security (when the United States Coast Guard is under the United States Department of Homeland Security and has not been transferred to the Department of the Navy under the Department of Defense). </P> <P> The individual in over-all charge of the Guantanamo military commissions is also called the convening authority, and it broadly mirrors the provisions found in the Uniform Code of Military Justice . The first three incumbents were civilian officials, although the first and third incumbents, John D. Altenburg and Bruce MacDonald, were retired military flag officers . Susan J. Crawford, the second convening authority, had been a long - term senior civilian lawyer for the Department of Defense, eventually serving as the Inspector General . </P>

Who is the general court martial convening authority