why does the military have their own court
Military justice The United States Constitution authorized the creation of a system of military justice. Article I, Section 8 permits the U.S. Congress to "make rules for the government and regulation of the land and naval forces."[26] Congress issued these rules first in 1806 as the Articles of War. Military justice during the American Civil War was governed by the 1863 Lieber Code. The Articles of War were superseded in 1951 by the Uniform Code of Military Justice (UCMJ).
Supreme Court Police The Supreme Court of the United States Police is a small U.S. federal law enforcement agency headquartered in the District of Columbia, whose mission is to ensure the integrity of the constitutional mission of the U.S. Supreme Court by protecting the Supreme Court building, the Justices, employees, guests, and visitors.[1] In accordance with 28 U.S.C. § 672, the Supreme Court Police falls under the jurisdiction of the Marshal of the United States Supreme Court who is appointed by the Supreme Court. The Marshal and the Supreme Court Police are authorized by 40 U.S.C. § 6121 to police the Supreme Court Building and protect the Justices, employees of the Court, and visitors to the Court.