President Trump's chief of staff John Kelly signed a memo late Tuesday allowing troops stationed at the border to act in a law enforcement capacity and use lethal force, if necessary, according to Tara Copp of Military Times.

The new “Cabinet order” was signed by White House Chief of Staff John Kelly, not President Donald Trump. It allows “Department of Defense military personnel” to “perform those military protective activities that the Secretary of Defense determines are reasonably necessary” to protect border agents, including “a show or use of force (including lethal force, where necessary), crowd control, temporary detention. and cursory search.”

...

Kelly said in the signed directive that the additional authorities were necessary because “credible evidence and intelligence” have indicated that the thousands of migrants who have now made their way to the U.S. checkpoint near Tijuana, Mexico, “may prompt incidents of violence and disorder” that could threaten border officials. -Military Times

Approximately 5,900 active-duty troops were deployed to the southern US border along with 2,100 national guard to reinforce the border and bolster enforcement efforts as thousands of asylum seekers from Central America arrive in Tijuana, Mexico in the hopes of pushing into the United States.

The Trump administration's move may raise concerns over the 1878 Posse Comitatus Act, which prohibits the use of federal military persojnnel to enforce domestic policies within the United States.

FULL STORY