The "virtual fence" stretching across hundreds of miles along the U.S. border with Mexico uses high-tech cameras and radar technology to detect immigrants trying to cross the border illegally.
Early technical problems and other glitches prompted security officials to consider scrapping the project altogether, The Christian Science Monitor said Wednesday.
The system uses an array of equipment meant to link border patrol agents across the border to nab suspects, but the software used has trouble telling the difference between shrubs, animals, or illegal immigrants, the newspaper said.
Richard Stana, a DHS overseer with the investigative arm of the U.S. Congress, the General Accounting Office, said at a congressional hearing on the project that it "did not fully meet user needs."
DHS officials, however, point to the some 2,400 illegal immigrants snared during the project, called Project 28, and note testing is ongoing to make necessary improvements.
But some congressional leaders remain skeptical. Rep. Bill Pascrell Jr., D-N.J., who sits on a national security committee, said at a February hearing, "After ... millions of dollars spent, we are no closer to a technological solution to securing the border. This is unacceptable."