AP sources: Secret Service director to leave Trump admin
Still, it comes amid a spate of turnover across DHS that began last week when Trump withdrew his Immigration and Customs Enforcement director's nomination to stay on permanently.
After Nielsen's departure, an empowered Stephen Miller, the immigration hawk White House senior adviser, is also eyeing the removal of Lee Francis Cissna, according to two of the people. Cissna is director of U.S. Citizenship and Immigration Services, which runs the legal immigration system.
Alles, a former Marine general, was recommended to the post by former White House chief of staff John Kelly.