A federal judge in San Francisco will hear arguments on whether military troops deployed this summer by the Trump administration to Los Angeles violated a federal law that bars troops from conducting law enforcement duties within the country.

On Saturday, Trump said the nation’s capital has become “one of the most dangerous cities anywhere in the World.” Last week he threatened to deploy the National Guard to D.C. and, as he has on several occasions since he was inaugurated in January, suggested that there should be a federal takeover.

President Donald Trump on Monday announced he is invoking the District of Columbia Home Rule Act to place the D.C. Metropolitan Police Department under direct federal control, a rare and controversial move.