Trial begins on whether deployment of National Guard to Los Angeles violated federal law

A federal judge in San Francisco is examining whether the Trump administration violated federal law by deploying National Guard troops and Marines to Los Angeles amid immigration protests.

California's Governor Gavin Newsom and city leaders opposed the deployment, which followed arrests by Immigration and Customs Enforcement. The state seeks to regain control of the troops and prevent military involvement in law enforcement.

The Posse Comitatus Act restricts military use for domestic policing. The Department of Defense authorized about 4,000 troops, with 250 remaining. Newsom initially gained a ruling that the administration overstepped its authority.

The Trump administration has appealed, asserting the need for troops to protect federal buildings amid protests. The case will address the limits of federal military authority in domestic situations.