Federal officials say they're ready to begin building a new "virtual fence" along the U.S.-Mexico border. The first towers holding sensors, cameras and communications gear to detect drug smugglers and illegal immigrants will be built along 53 miles of Arizona's border with Mexico. Towers on the remaining 320 miles of the state's southern border will follow.
They expect it to cover nearly the entire 2,000-mile boundary within five years. The executive director of the Homeland Security Department's Secure Border Initiative program tells The Associated Press that construction could start within weeks.