Before entering academics, Rizer worked at the U.S. Department of Justice (DOJ) for nine years as a trial attorney. His most recent assignment at DOJ was as a prosecutor in the Criminal Division working on narcotics and national security cases, primarily focused on international drug cartels and narco-terrorists. His other postings at DOJ included national security litigator with the Federal Program’s Guantanamo Bay Litigation Team, prosecutor in the U.S. Attorney’s Office for the Southern District of California, and civil litigator with the Office of Immigration Litigation.