Homeland Security Secretary Janet Napolitano. Kevin Dietsch /UPI/Landov hide caption itoggle caption Kevin Dietsch /UPI/Landov The Two-Way Homeland Security Secretary Napolitano Is Stepping Down July 12, 2013 She is to become the University of California's next president. Confirmation of a successor could take time. Speculation on a successor has already begun. Perhaps former Sen. Joe Lieberman?