Mullin said DHS will comb through voter rolls in search of noncitizens.
It might cost more to apply to become a United States citizen if a rule proposed by the Trump administration is enacted.
A federal judge has blocked an attempt by the Trump administration to subpoena Minnesota Gov. Tim Walz and other state officials, calling it an effort to "harass and retaliate against them."
President Donald Trump signed a bill into law on Wednesday that gives his immigration and deportation agenda nearly $70 billion for the rest of his term.
A spokesperson told ABC News that Air France boarded a passenger from the Democratic Republic of Congo "in error" on a flight to the United States.
President Donald Trump has signed a bill funding much of the Department of Homeland Security and ending the longest agency shutdown in history.