The Homeland Security Department months ago started collecting biometric information on every refugee who is referred for resettlement in the U.S., and it retains the data even if those people never set foot in the country.
Every year, the United Nations High Commissioner for Refugees sends profiles on tens of thousands of refugees to federal agencies, which uses that information to determine if the person can enter the country. Those profiles contain biographic information like name, birthday and country of origin, and as of late, they also include biometric data.
In January, the UNHCR entered an agreement with U.S. Citizenship and Immigration Services to share fingerprints, iris scans, face images and other biometric data on the refugees it refers for resettlement in the U.S.