A Department of Homeland Security (DHS) appropriations bill released on 9 January allocates US$3 million in funding for testing of a biometric exit app that would be used by Customs and Border Protection (CBP).The funding will be used for a biometric exit mobile application demonstration at two airports, according to an explanatory note added to the bill.The idea of implementing an exit system at all US ports of entry was first touted in 1996 as part of the “Illegal Immigration Reform and Immigrant Responsibility Act”.Three related laws passed since the 9/11 attacks – based on 9/11 Commission recommendations – required that biometrics such as fingerprints and facial data be used to verify identities as part of the scheme.The funds provided to test the biometric exit mobile app testing are part of $10.7 billion allocated for CBP, an increase of $118.7 million above the FY 2014 enacted level. Overall, the bill granted $39.7 billion in discretionary funding for the DHS, an increase of $400 million compared to the FY 2014 enacted level.”The funding in this bill is targeted to critical security and law enforcement efforts that keep our nation and people safe, and ensure the laws of the land are strongly enforced,” said House Appropriations Committee Chairman Hal Rogers.A day after the bill was released, Republican representative Candice S Miller introduced legislation that “requires the Secretary of Homeland Security to establish a biometric exit data system”.Last September, Miller also introduced the Biometric Exit Improvement Act of 2013, which had the same requirement. That bill also would've given the DHS just 180 days to submit an implementation plan to establish a biometric exit data system.Proponent say a biometric exit system would fulfil long-held goals of the federal government to obtain accurate and timely data on those who overstay visas.Janice Kephart, former special counsel at the Senate Committee on the Judiciary and former counsel to the 9/11 Commission, has estimated that the first-year implementation costs for all air and sea ports would range from $400 million to $600 million, even assuming significant cost overruns.Currently, the US relies on the US-VISIT system, which involves the collection and analysis of biometric data (such as fingerprints) by the Office of Biometric Identity Management. These are checked against a database to track individuals deemed by the United States to be terrorists, criminals, and illegal immigrants.