Many politicians are worried that terrorists hidden among the illegal immigrants, asylum seekers, and unaccompanied alien children are currently crossing the Southwest border from Mexico. The most recent example is a brutal grilling of Department of Homeland Security secretary Alejandro Mayorkas by Representative Dan Bishop (R‑NC). In that interview, the secretary even stated that “known or suspected terrorist — KST is the acronym that we use — individuals who match that profile have tried to cross the border, the land border, have tried to travel by air into the United States not only this year, but last year, the year prior, so on and so forth.”

Here are the facts about terrorists crossing the border from Mexico: Zero people have been killed or injured in attacks on U.S. soil committed by terrorists who illegally crossed the Southwest border. From 1975 through the end of 2020, only nine people convicted of planning a terrorist attack entered the United States illegally – some of them on ships, airplanes, and walking across the border. For instance, the most serious case was Walid Kabbani who walked across the Canadian border with a bomb in 1987 and was immediately arrested. Only three of the nine who entered illegally came across the border with Mexico as young children in 1984, 23 years before they were arrested for a comically planned terrorist attack on Fort Dix in 2007. They were Shain Duka, Britan Duka, and Eljvir Duka.

The reporting about whether terrorists are crossing the border is not clear and many people are confusing and conflating known or suspected terrorist (KST), being the terrorist watchlist, and what it means to be a Special Interest Alien (SIA) when talking about the risk of terrorism on the border. Secretary Mayorkas may have even done so yesterday. According to the Department of Homeland Security (DHS), a known terrorist is “an individual who has been (a) arrested, charged by information, indicted for, or convicted of a crime related to terrorism and/​or terrorist activities by U.S. Government or foreign government authorities; or (b) identified as a terrorist or a member of a terrorist organization pursuant to statute, Executive Order, or international legal obligation pursuant to a United Nations Security Council Resolution.” A suspected terrorist “is an individual who is reasonably suspected to be engaging in, has engaged in, or intends to engage in conduct constituting, in preparation for, in aid of, or related to terrorism and/​or terrorist activities.”

A Special Interest Alien (SIA) is an apprehended border crosser from a country that the U.S. government has deemed a potential source of terrorism. As David Bier and I wrote years ago, there isn’t an updated go-to list of countries where SIAs come from and the lists that are released keep changing.

Those on the terrorist watch list, known as the Terrorism Screening Database, are deemed a terrorism risk by the government and it includes 1.16 million names as of 2017. Most of those names are foreigners, but since there have only been 72 foreign-born terrorists who have committed or attempted to commit attacks on U.S. soil from 2002–2017, only a handful of people on the list are likely to be real terrorists – if that.

There is some overlap between those three terms as an individual can be a KST on a watchlist and an SIA, but that doesn’t mean that all SIAs are KSTs or even on a watchlist. To make it more confusing, KSTs are on the watchlist but not everybody on the watchlist is a KST. Axios has reported that since October 2020, at the beginning of the 2021 fiscal year, four people have been apprehended along the Southwest Border whose names matched those of names of people in the terrorism watchlist database. In 2017, the government stopped about 3,700 people on the terrorist watchlist from entering the United States – most of them trying to enter via air. Four people on the terrorist watchlist being apprehended by Border Patrol along the border during a six month period is not evidence of an uptick. We need more information on these people and to know that they were actually the people on the watchlist rather than just sharing a name, but there is no evidence of a plot to commit an attack on U.S. soil.

Furthermore, many people are conflating SIAs with KSTs and individuals on the watchlist. This is an even more egregious error. From 2007 through the end of 2019, Border Patrol apprehended 91,132 SIAs from countries that have ever spent time on the publicly available SIA lists (Table 1). SIAs accounted for 1.39 percent of all immigrants apprehended by Border Patrol during that time.

Not a single one of the 91,132 was convicted for carrying out, attempting to carry out, or planning a terrorist attack on U.S. soil. The Dukas, the only three terrorists to have crossed the U.S. border with Mexico, are ethnic Albanians from Macedonia. Neither country has appeared on any SIA list. The only terrorists who crossed the border with Mexico illegally did so as children decades before becoming terrorists and were not even from SIA countries. That’s just more reason to repeat what DHS wrote: “These KST and SIA figures are not the same and should not be conflated.”

Terrorism is a serious subject, taking it seriously means not inflating the risk in the midst of a very real humanitarian crisis. A core job of the U.S. government is to protect the life, liberty, and property inside of the United States. Protecting Americans requires accurate assessments of threats and not wild speculation without evidence. We have too much of the latter, not enough of the former.