MEXICO CITY - A high-tech "virtual wall" will detect more than 95 percent of illegal crossings at the busiest jumping-off point along the U.S.-Mexico border, the U.S. Border Patrol chief said Thursday.
In a videoconference with reporters in Mexico, David Aguilar predicted the so-called "virtual wall" of lights, ground sensors and cameras - reinforced by more agents - will essentially halt illegal crossings along the Arizona border, the busiest section for clandestine entries.
Officials expect to complete 28 miles of the high-tech system in Arizona by June, and by next year it should run into New Mexico and parts of Texas.
Eventually, the integrated system will cover sections along the entire border, from San Diego to Brownsville, Texas.
"We will be able to identify, detect and classify more than 95 percent of illegal entries with the virtual wall," Aguilar said.
Detentions along the U.S.-Mexico border already have dropped by 30 percent from October 2006 to this week, compared to the same period last year, Aguilar said - a reduction officials attribute to fewer attempted crossings. In 2006, 1.1 million migrants were detained.
He attributed the fall to President Bush's deployment of 6,000 National Guard troops to the border, the addition of more than 700 Border Patrol agents this fiscal year and new strategies.
Along a 210-mile stretch in west Texas, detentions have dropped 65 percent since the start of a federal project called Operation Streamline, which jails and prosecutes any illegal immigrant caught crossing there.
Aguilar said far fewer immigrants have been seen at traditional staging points in Mexico and that agents have not seen a shift to new crossing areas along the border.
Congress has approved 700 miles of fence for the border and has allowed officials to decide whether to build metal fences or virtual walls.
Aguilar expects most of the distance will be covered by the virtual barrier, with metal walls kept to a minimum.
The U.S. government is adding 70 miles of metal walls this year and 225 miles next year. The barriers are being built primarily in Arizona, which has seen the largest flow of illegal migrants since a U.S. crackdown in Texas and California more than a decade ago funneled people into its remote desert.
Mexican President Felipe Calderon has likened the barriers to the Berlin Wall.