Southwest Border Security: Border Patrol is Deploying Surveillance Technologies but Needs to Improve Data Quality and Assess Effectiveness [open pdf - 6MB]
"The southwest border has long been vulnerable to cross-border illegal activity. In fiscal year 2016, Border Patrol apprehended over 409,000 illegal entrants. Border Patrol has employed a variety of land-based surveillance technologies to assist in securing the border. GAO [Government Accountability Office] has reported regularly on CBP's [Customs and Border Protection] progress and challenges deploying surveillance technologies. GAO was asked to review CBP's use of surveillance technology. This report examines (1) the deployment status of surveillance technology programs and the extent to which CBP has developed plans for future technology deployments and (2) what data are available on the contributions of deployed technologies to CBP's border security efforts and the extent to which CBP has assessed technology performance."
Government Accountability Office: http://www.gao.gov/