Posse Comitatus Act

The Posse Comitatus Act is a (, original at ) signed on June 18, 1878, by. The purpose of the act – in concert with the – is to limit the powers of the  in using  to enforce  within the. It was passed as an amendment to an army following the end of  and was updated in 1956 and 1981.

The act specifically applies only to the and, as amended in 1956, the. Although the act does not explicitly mention the and the, the  has prescribed regulations that are generally construed to give the act force with respect to those services as well. The act does not prevent the or the   under  authority from acting in a  capacity within its home state or in an adjacent state if invited by that state's governor. The, which operates under the , is not covered by the Posse Comitatus Act either, primarily because although the Coast Guard is an , it also has both a enforcement mission and a federal regulatory agency mission.

The title of the act comes from the legal concept of , the authority under which a county sheriff, or other law officer, conscripts any able-bodied person to assist in keeping the peace.

History
The Act, § 15 of the appropriations bill for the Army for 1879, found at, was a response to, and subsequent prohibition of, the of the former  by the  during the twelve years of  (1865–1877) following the  (1861–1865). The president withdrew federal troops from the Southern States as a result of a compromise in one of the most disputed national elections in American history, the. of, the candidate, defeated  candidate  of  in the popular vote. Tilden garnered 184 to Hayes' 165; 20 disputed electoral votes remained uncounted. After a bitter fight, Congress struck a deal resolving the dispute and awarded the presidency to Hayes.

In return for Southern acquiescence regarding Hayes, Republicans agreed to support the withdrawal of federal troops from the former Confederate States, formally ending Reconstruction. Known as the, this agreement involved allowing South Carolina, Florida, and Louisiana to agree to certify Rutherford B. Hayes as the president in exchange for the removal of federal troops from the South.

The places primary responsibility for the holding of s in the hands of the individual states. The maintenance of peace, conduct of orderly elections, and prosecution of unlawful actions are all state responsibilities, pursuant of any state's role of exercising police power and maintaining law and order, whether part of a wider federation or a unitary state. During the local, state, and federal elections of 1874 and 1876 in the former Confederate States, all levels of government chose not to exercise their police powers to maintain law and order. Some historians have concluded most Reconstruction governments did not have the power to suppress the violence.

When the and  from the former Confederate States reached Washington, they set as a priority legislation to prohibit any future president or Congress from directing, by military order or federal legislation, the imposition of federal troops in any U.S. state. By the 1878 election, Congress was dominated by the Democratic Party which passed the Posse Comitatus Act in 1878. The Act did not end the conflict, as the 1879 Rider Wars led to the second longest shutdown of the US government. According to historian Heather Cox Richardson, railroad executive convinced President Hayes to use federal troops to end the, causing a backlash that motivated bipartisan support for the Posse Comitatus Act.

In the mid-20th century, the administration of President used an exception to the Posse Comitatus Act, derived from the, to send federal troops into , during the. The Arkansas governor had opposed desegregation after the ruled in 1954 in the  that segregated public schools were unconstitutional. The, among other powers, allow the president to call up military forces when state authorities are either unable or unwilling to suppress violence that is in opposition to the constitutional rights of the people.

The original Posse Comitatus Act referred mostly to the United States Army. The, which had been incorporated within the Army inside the U.S. (and the Navy outside) until 1949, was added in 1956. This law is often relied upon to prevent the Department of Defense from interfering in domestic law enforcement. The is not included in the act even though it is one of the five armed services because it is not a part of the Department of Defense. At the time the act became law, the modern Coast Guard did not exist. Its predecessor, the, was primarily a customs enforcement agency and part of the. In 1915, when the Revenue Cutter Service and the were amalgamated to form the Coast Guard, the service was both explicitly made a military branch and explicitly given federal law enforcement authority.

Legislation
The original provision was enacted as Section 15 of chapter 263, of the Acts of the 2nd session of the. "15. From and after the passage of this act it shall not be lawful to employ any part of the Army of the United States, as a posse comitatus, or otherwise, for the purpose of executing the laws, except in such cases and under such circumstances as such employment of said force may be expressly authorized by the Constitution or by act of Congress; and no money appropriated by this act shall be used to pay any of the expenses incurred in the employment of any troops in violation of this section and any person willfully violating the provisions of this section shall be deemed guilty of a misdemeanor and on conviction thereof shall be punished by fine not exceeding ten thousand dollars or imprisonment not exceeding two years or by both such fine and imprisonment"

The text of the relevant legislation is as follows:
 * . Use of Army and Air Force as posse comitatus
 * Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.

Also notable is the following provision within (which concerns generally the organization and regulation of the armed forces and Department of Defense):


 * . Restriction on direct participation by military personnel
 * The shall prescribe such regulations as may be necessary to ensure that any activity (including the provision of any equipment or facility or the assignment or detail of any personnel) under this chapter does not include or permit direct participation by a member of the Army, Navy, Air Force, or Marine Corps in a search, seizure, arrest, or other similar activity unless participation in such activity by such member is otherwise authorized by law.

2006–07 suspension
In 2006, Congress modified the Insurrection Act as part of the ( as of 2008). On September 26, 2006, urged Congress to consider revising federal laws so that U.S. armed forces could restore public order and enforce laws in the aftermath of a natural disaster, terrorist attack or incident, or other condition. were included in the, which was signed into law on October 17, 2006.

Section 1076 is titled "Use of the Armed Forces in major public emergencies." It provided that: "The President may employ the armed forces ... to ... restore public order and enforce the laws of the United States when, as a result of a natural disaster, epidemic, or other serious public health emergency, terrorist attack or incident, or other condition ... the President determines that ... domestic violence has occurred to such an extent that the constituted authorities of the State or possession are incapable of maintaining public order ... or [to] suppress, in a State, any insurrection, domestic violence, unlawful combination, or conspiracy if such ... a condition ... so hinders the execution of the laws ... that any part or class of its people is deprived of a right, privilege, immunity, or protection named in the Constitution and secured by law ... or opposes or obstructs the execution of the laws of the United States or impedes the course of justice under those laws.''"

In 2008, these changes in the of 1807 were, reverting to the previous wording of the Insurrection Act. It was originally written to limit presidential power as much as possible in the event of insurrection, rebellion, or lawlessness.

2011 modification
In 2011, President signed  into law. Section 1021(b)(2) extended the definition of a "covered person", i.e., someone possibly subject to detention under this law, to include: "A person who was a part of or substantially supported, the, or associated forces that are engaged in hostilities against the United States or its coalition partners, including any person who has committed a belligerent act or has directly supported such hostilities in aid of such enemy forces."Section 1021(e) purports to limit the scope of said authority with the text, "Nothing in this section shall be construed to affect existing law or authorities relating to the detention of United States citizens, lawful resident aliens of the United States, or any other persons who are captured or arrested in the United States."

Exclusions and limitations
There are a number of situations in which the Act does not apply. These include:
 * Army and Air National Guard units, s, and s while under the authority of the.
 * Federal armed forces used in accordance to the, as was the case with the and  being sent to curtail the.
 * Under, the may request that the  provide emergency assistance if domestic law enforcement is inadequate to address certain types of threats involving the release of , such as potential use of a  or . Such assistance may be by any personnel under the authority of the Department of Defense, provided such assistance does not adversely affect U.S. military preparedness. The only exemption is the deployment of nuclear materials on the part of the United States Armed Forces.
 * Support roles under the.
 * Provide surveillance, intelligence gathering, observation, and equipment for domestic law enforcement on operations such as drug interdiction and counter-terrorism missions.

Exclusion applicable to U.S. Coast Guard

 * See the and  for more information on U.S. Coast Guard law enforcement activities.

Although it is an armed service, the U.S. Coast Guard, which operates under the during peacetime, is not only not restricted by the Posse Comitatus Act but has explicit authority to enforce federal law. This is true even when the Coast Guard is operating as a service within the during wartime.

In December 1981, the was enacted clarifying permissible military assistance to domestic law enforcement agencies and the Coast Guard, especially in combating  into the United States. Posse Comitatus clarifications emphasize supportive and technical assistance (e.g., use of facilities, vessels, and aircraft, as well as intelligence support, technological aid, and surveillance) while generally prohibiting direct participation of U.S. military personnel in law enforcement (e.g., search, seizure, and arrests). For example, a U.S. Navy vessel may be used to track, follow, and stop a vessel suspected of drug smuggling, but Coast Guard (LEDETs) embarked aboard the Navy vessel would perform the actual boarding and, if needed, arrest the suspect vessel's crew.

Advisory and support roles
Federal troops have a long history of domestic roles, including occupying secessionist Southern states during Reconstruction and putting down major urban riots. The Posse Comitatus Act prohibits the use of active duty personnel to "execute the laws"; however, there is disagreement over whether this language may apply to troops used in an advisory, support, disaster response, or other homeland defense role, as opposed to domestic law enforcement.

On March 10, 2009, members of the from  were deployed to, in response to. Samson officials confirmed that the soldiers assisted in traffic control and securing the crime scene. The did not request military assistance nor did President  authorize their deployment. Subsequent investigation found that the Posse Comitatus Act was violated and several military members received "administrative actions".