Given the alarming expansion of terrorist safe havens across the Middle East and North Africa, along with the increasing sophistication of these groups in organizing and planning attacks, it is imperative the Department of Homeland Security is properly prepared to detect and deter nuclear threats. The Domestic Nuclear Detection Office, which we often refer to as DNDO, is the entity within the Department of Homeland Security responsible for preventing a nuclear attack and is the lead agency within the United States Government for coordinating efforts to detect and intercept radiological and nuclear devices that may find their way into the United States. DNDO works with other Department of Homeland Security components, including Customs and Border Protection, as well as State and local law enforcement to provide these entities with the equipment and training needed to interdict radiological or nuclear material before it can enter the United States. DNDO also works with State and local law enforcement and first responders to strengthen nuclear detection capabilities in the interior. While these achievements are significant, there is still work to be done to address the gaps in the nuclear detection architecture.