"Lying in state is the rare honor granted by the United States to a deceased official whereby his or her remains are placed in the rotunda of the United States Capitol in Washington, D.C., for public viewing. The casket is guarded by members of the armed forces. By regulation and custom, only Presidents, military commanders, and members of Congress are granted the honor of lying in state. Except for Presidents and former Presidents, the honor is not automatic. "
Who'd decides who gets this honour?