A U.S. court has ruled that then-President Donald Trump's deployment of the National Guard and Marines to Los Angeles in June of last year was illegal.

According to the Associated Press and other sources on September 2 (local time), Judge Charles Breyer of the U.S. District Court for the Northern District of California in San Francisco ruled that Trump's actions violated the Posse Comitatus Act, a law enacted in the 19th century that strictly prohibits the military from engaging in domestic law enforcement.

In his ruling, Judge Breyer stated, "While the need for federal agents to perform their duties safely is clear, mobilizing the military for this reason goes too far." He added that deploying military personnel for traffic control, perimeter security, and riot suppression undermined the fundamental purpose of the Posse Comitatus Act. However, the judge stayed the ruling's effect until September 12 to allow for an appeal.

Last summer, in response to violent protests that arose during an immigration enforcement operation, Trump had federalized the California National Guard, deploying 4,000 troops to L.A. He also dispatched an additional 700 Marines. While most of the troops have since been withdrawn, approximately 300 National Guard members remain.

The ruling came in response to a lawsuit filed by California Governor Gavin Newsom and Attorney General Rob Bonta, both Democrats, who argued that Trump's actions were an illegal overreach of presidential and federal government authority. Immediately after the ruling, Governor Newsom stated on social media, "Californians stopped Trump's illegal militarization of our cities."

Reuters reported that the Trump administration is expected to appeal the decision and that the ruling's effect is limited to the state of California.