Chad Wolf steps down as acting secretary of homeland security; FEMA administrator Peter Gaynor to take over Wolf's resignation came less than a week after he pledged to remain in office and just 10 days before the inauguration of President-elect Joe Biden The Associated Press January 12, 2021 12:57:31 IST File image of acting Secretary of Homeland Security Chad Wolf. AP Washington: President Donald Trump’s acting head of the Department of Homeland Security abruptly resigned Monday, leaving the post ahead of schedule as the nation faces a heightened terrorism threat from extremists seeking to reverse the election. The announcement by acting DHS Secretary Chad Wolf was perplexing. It came less than a week after he pledged to remain in office and just 10 days before the inauguration of President-elect Joe Biden. Wolf cited a legal challenge to his leadership as a reason for his resignation, but that had surfaced months ago.