Desmond Holly and several school shooters in the past year were active on the same website, the ADL says.

The move amounts to a sweeping reversal of "sanctuary" policies in the nation's capital, allowing the Metropolitan Police Department, for the time being, to fully cooperate with federal immigration enforcement.

The U.S. is considering dropping leaflets on Caracas as a kind of psychological warfare to pressure Venezuelan President Nicolás Maduro, multiple U.S. officials familiar with the talks told CBS News.