 A group associated with ISIS-K. Fox's Matt Finn asked him about it in Tucson. DHS confirms that at least 400 migrants with potential ISIS ties recently crossed into the United States. That is incorrect. Homeland Security Secretary Alejandro Mayorkas shooting down his own department's information during a border visit. A Department of Homeland Security senior official tells Fox News it's identified more than 400 subjects of concern who came to the U.S. through an ISIS-affiliated human smuggling network.