U.S. Customs and Border Patrol agents stationed at the U.S.-Mexico border only stopped six immigrants between October 2017 and March 2018 who were on the government’s list of known or suspected terrorists, according to data cited Monday in a report from NBC News. NBC’s report casts serious doubt on Press Secretary Sarah Huckabee Sanders’ Friday claim that border patrol agents stopped 4,000 known or suspected terrorists throughout the entire fiscal year. The White House has repeatedly used that number to back Trump’s demand for a border wall, and justify his decision to keep the government shut down until Congress passes a bill to fund it. Overall, 41 people crossing the U.S.-Mexico border during that six-month period were on the terrorism list—but 35 of those people were U.S. citizens or lawful permanent residents.