BRIEF SUMMARY IF YOU’RE BUSY, FULL ARTICLE BELOW: Concerns are growing over the potential exploitation of the U.S.-Mexico border by known or suspected terrorists following the recent terrorist attacks by Hamas in Israel. Critics, including Republican lawmakers and conservative media figures, argue that the Biden administration’s border policies may provide an easier entry for terrorists. Former President Donald Trump claimed that the “same people” responsible for attacks in Israel are coming across the southern border, though he provided no evidence. While Border Patrol has seen a spike in apprehensions of individuals with matches on the U.S. terror watchlist, they constitute a small fraction of overall migrants processed along the border. Valid concerns persist about the tools available to detain national security threats entering the country clandestinely. In fiscal year 2023, Border Patrol reported a record-high of 151 migrants with positive terrorism watchlist matches apprehended along the U.S.-Mexico border, highlighting the need for enhanced security measures.

Concerns about whether known or suspected terrorists are exploiting the migration crisis along the U.S.-Mexico border to enter the country have intensified following the brutal terrorist attacks carried out by Hamas in Israel over the weekend.

Republican lawmakers, GOP White House hopefuls and conservative media figures have argued that the Biden administration’s border policies have given terrorists an easier way to enter the U.S. and harm Americans. On Monday, former President Donald Trump claimed that the “same people” who killed or abducted more than 1,000 civilians in Israel are coming across the southern border separating the U.S. and Mexico, offering no evidence to support his assertion.

There has been a marked increase in Border Patrol apprehensions of individuals with matches on the U.S. terror watchlist over the past two years. But they represent a tiny fraction of all migrants processed along the southern border. Such incidents are more common along the U.S.-Canada border, and not all those on the watchlist are suspected terrorists.

Still, there are valid concerns about whether the U.S. has sufficient tools to ensure it detains all national security threats, including those entering the country clandestinely.

“Are terrorists flooding across the border? Probably not,” said Theresa Cardinal Brown, a former Department of Homeland Security official under Presidents George W. Bush and Barack Obama. “But at the same time, it is true that the large number of people arriving does have national security implications.”

Here’s what we know about this issue, based on government data, reports and policy:

A spike in terror watchlist hits along the U.S.-Mexico border

When Border Patrol apprehends individuals, it is supposed to run criminal and national security screenings on them. The process includes checking names against the Terrorist Screening Data Set, or TSDS, an FBI system that tracks known or suspected terrorists as well as their affiliates.

Border Patrol apprehensions of individuals on the FBI’s terrorism watchlist have increased sharply in recent years as the number of overall crossings recorded by the agency along the U.S.-Mexico border has soared to record levels.

In fiscal year 2023, Border Patrol reported apprehending 151 migrants with positive terrorism watchlist matches who entered the U.S. illegally along the southern border, an all-time high for the region that eclipsed the previous record of 98 set in fiscal year 2022, government figures show. In fiscal year 2021, the agency reported just 15 such apprehensions.

When including those processed at official ports of entry, there were 227 terror database hits with individuals processed along the southern border in fiscal year 2023.