Border Patrol agents apprehend 15 suspects on the FBI's terrorist watch list at the southern border

Border Patrol agents at the U.S. southern border apprehended 15 people last month who were on the FBI's terrorist watchlist. 

That figure is a record for number of people caught on the watch list any month, and equal to the total number apprehended during all of the previous year.

Beyond those on the list, a record 240,000 illegal immigrants crossed the border in May and were apprehended by the Customs and Border Protection agency. The agency, however, only sends back about half of the individuals it encounters, meaning the rest are either released outright at the border, or transferred to other government agencies, many of which go on to release them as well.

The numbers released by CBP are considered a rough measurement of the actual figures, because, of course, some number of migrants get across the border undetected. This additionally means that the 15 individuals on the FBI's terror watch list are potentially not the only people on that list who have attempted to enter the country.

Last month, federal prosecutors revealed that they had caught an Iraqi man attempting to carry out an assassination attempt on former President George W. Bush's life. The man said he was planning to bring an ISIS hit squad into the country via the southern border.

At the time, Trump administration CBP director Mark Morgan said, "I’m concerned that the next terrorist attacker is already in the United States because of this administration’s open border policies," citing the "legitimate national security vulnerability on our southern border."

"While DHS has accounted for 50 individuals found on the terror watchlist attempting to enter the country just this year, recent reports of the staggering number of known 'got-aways' would indicate that we cannot be certain exactly how many watch-listed individuals have entered the United States amidst the chaos at our southwest border," retiring Rep. John Katko (R-N.Y.) told the Washington Times.