Trump deployed the National Guard and declared federal control of DC police. Here’s how he is able to do it

(CNN) — The DC National Guard began appearing in the nation’s capital on Tuesday after President Donald Trump announced a day earlier he is deploying guard troops and placing Washington, DC’s police department “ under direct federal control,” citing a public safety emergency after an assault on a former government worker.

CNN observed five armored personnel carriers near the Washington Monument on Tuesday evening. The DC National Guard reports only to the President of the United States. The city’s status as a district, not a state, allows the president, and in turn the federal government, more leeway in directing troops and a range of federal authorities.