By Joel Gehrke • 3/1/16 1:22 PM

U.S. Customs and Border Protection officials have "situational awareness" of what happens on about half of the southern border, but they don't know how many people are trying to enter the country illegally.

"About 56 percent of the border is deployed in a way that agents and/or our technology can see activity in real time," Ronald Vitiello, acting chief of U.S. Border Patrol, told a House Homeland Security subcommittee panel.

A trio of government officials were invited to discuss the effectiveness of the Border Patrol, but the testimony raised questions for members about how much of the border is actually secure and whether Department of Homeland Security statistics overstate the Border Patrol's effectiveness.

"The southwest border continues to be vulnerable to cross-border illegal activity, and DHS reported apprehending over 331,000 illegal entrants and making over 14,000 seizures of drugs in fiscal year 2015," Rebecca Gambler, one of the witnesses, said in her prepared statement to the panel.

But Vitiello conceded that the Border Patrol doesn't know how many people are trying to cross the border. "I won't sit here today and tell you that we know exactly what the denominator is," he said.

Statistics measuring the Border patrol's effectiveness in catching illegal immigrants are boosted by apprehensions made by local law enforcement, as well as by unaccompanied children who turn themselves in voluntarily. "It would affect the effectiveness rate," Vitiello said.

Rep. Martha McSally, R-Ariz., urged Vitiello to provide data on how many apprehensions the Border Patrol makes of people who are trying to escape detection. "If the formula does include those who are not evading apprehension, then that skews the formula," she said. "You should be measuring the number that were evading apprehension."

http://www.washingtonexaminer.com/bo...rticle/2584603