A U.S. judge on Monday blocked plans to move the FBI’s headquarters to a federal office building in Washington, finding that President Donald Trump’s administration illegally tossed out a previously approved plan to build a new facility nearby in Maryland.

The ruling is the latest development in a yearslong battle over where to house the main office for the nation’s premier law enforcement agency. A site in Greenbelt, Maryland, was picked during former President Joe Biden’s administration, but Trump appointees sought to reverse that decision last year in favor of repurposing the Ronald Reagan Building, a federal office complex a few blocks from the FBI’s existing headquarters.