GAO said in a report published Wednesday that DHS should also evaluate the reliability of its data on overstays.
The congressional audit agency’s report aims to discuss the efforts DHS has made since GAO issued its initial report in July 2013.
Officials at DHSâ Customs and Border Protection told GAOÂ that as of January 2016, they have initiated steps to craft the evaluation framework for the biometric exit system, including the development of metrics designed to assess the performance of biometric air exit platforms.
According to the report, DHS has started to assess biometric exit systems at airports, including a mobile device that CBP tested at 10 airports.
The handheld tool works to gather biometric exit and biographic information from tourists who are foreign nationals.