Border Security: Security Vulnerabilities at Unmanned and Unmonitored U.S. Border Locations, Statement of Gregory D. Kutz, Managing Director Forensic Audits and Special Investigations, John W. Cooney, Assistant Director Forensic Audits and Special Investigations, Testimony Before the Committee on Finance, U.S. Senate [open pdf - 1MB]
"This testimony will address what GAO [Government Accountability Office] investigators found during a limited security assessment of seven border areas that were unmanned, unmonitored, or both-four at the U.S.-Canada border and three at the U.S.-Mexico border. In three of the four locations on the U.S.-Canada border, investigators carried a duffel bag across the border to simulate the cross-border movement of radioactive materials or other contraband. Safety considerations prevented GAO investigators from attempting to cross north into the United States from a starting point in Mexico."
U.S. Senate Committee on Finance: http://finance.senate.gov/