Justice Department Releases Opinion on Military Arrests Near Borders
The Office of Legal Counsel asserted that arrests by military personnel near national defense areas do not violate the Posse Comitatus Act.
On Aug. 14, the Department of Justice’s Office of Legal Counsel (OLC) released a 15-page memorandum contending that the Posse Comitatus Act does not prohibit military personnel from effecting arrests in the “immediate vicinity” of a designated “national defense area” for alleged crimes there. The opinion followed President Trump’s April 2025 order designating swaths of the Mexico-U.S. border as national defense areas.
The Posse Comitatus Act generally restricts the use of the military for law enforcement purposes on U.S. soil. However, members of the military are able to operate in national defense areas with authorities usually reserved for law enforcement officials, including seizure and arrest powers.
The OLC memo seeks to expand that exception for military installations under the Posse Comitatus Act, arguing members of the military can, for example, arrest purported trespassers who have left but are still near the area. The OLC opinion states:
Even though substantial portions of the NDAs may be presently unoccupied or have no standing structures on them, there is a military necessity to ensure that unauthorized persons are not establishing a position to monitor the activities of U.S. forces for intelligence gathering purposes or conducting reconnaissance in preparation for a terrorist attack. Individuals may also be drawn to remote and unoccupied locations to engage in criminal activity, which poses a threat to military personnel who may come upon them in the course of their duties or where the activity itself poses a danger, such as the operation of methamphetamine laboratories. As there is no way for military personnel to know a priori the identity or intent of an unauthorized person, there is a military purpose in apprehending, at least temporarily, anyone whose presence is unauthorized, in order to ensure appropriate measures can be taken to protect national security and the safety of military personnel. That military purpose continues even if the trespassers have exited the installation before they were apprehended.
Read the OLC opinion here or below:
