Border apprehensions decreased by 91 percent in the San Diego sector from the 1994 fiscal year, right after the original fencing was completed, to the 2018 fiscal year. But, according to the Congressional Research Service, “the primary fence, by itself, did not have a discernible impact on the influx of unauthorized aliens coming across the border in San Diego.” Instead, a combination of additional staffing and new technology is what proved effective — in addition to the fencing. Over all, border crossings have been declining for nearly two decades even in areas without barriers.