U.S. Marines detained Army veteran Marcos Leao for two hours outside Wilshire Federal Building; no charges filed

On June 13, 2025, U.S. Marines from the 2nd Battalion, 7th Marine Regiment — deployed to Los Angeles under Title 10 authority as part of operations supporting federal immigration enforcement — detained Marcos Leao, a U.S. Army veteran, outside the Wilshire Federal Building. Marines zip-tied Leao's hands behind his back and held him for approximately two hours before releasing him without charges or explanation. Leao had not been accused of any crime, and no arrest was made.

Legal experts and civil liberties advocates immediately identified the incident as the first known instance of active-duty military personnel detaining a civilian during the Los Angeles deployment and raised serious Posse Comitatus Act concerns. The Act (18 U.S.C. § 1385) prohibits active-duty military from executing civil law — including detentions and arrests — unless Congress has specifically authorized it through mechanisms such as the Insurrection Act. No such invocation had been made for the Los Angeles operation; the Marines were deployed under Title 10 support authority, not law enforcement authority. Prior to the detention, DHS Secretary Kristi Noem had sent a letter to Defense Secretary Pete Hegseth requesting that military forces deployed at federal facilities be granted authority to detain or arrest civilians — a letter leaked to and published by the San Francisco Chronicle on June 9.

The detention of Leao marks the first documented exercise of a de facto military detention function during the Los Angeles deployment, which had been established following Trump's § 12406 federalization of California National Guard units on June 7, 2025. Active-duty forces performed a law enforcement act — detention without probable cause, without charge, and without statutory authority — that the Posse Comitatus Act reserves exclusively to civilian law enforcement. The Noem letter establishes that the administration was actively seeking detention authority it did not yet legally possess at the time Marines detained Leao.