A consortium of researchers dedicated to improving the understanding of the human causes and consequences of terrorism

Border Crossings and Terrorist Attacks in the US

New report examines trends, screening process opportunities

In a new report, researchers from the National Consortium for the Study of Terrorism and Responses to Terrorism (START) examine U.S. border crossings by individuals indicted between 1980 and 2004 on federal terrorism charges.

Based upon information available in public court documents, the research team, comprised of scholars at the University of Maryland and at the University of Arkansas, identified 264 indicted individuals who had been involved in 221 border crossings at 22 U.S. ports of entry, and who were associated with 43 known U.S. terrorist attacks since 1970. In the study, "Border Crossings and Terrorist Attacks in the United States," the research team found the border crossers who had been indicted on terrorism charges were most often U.S. citizens entering back into the United States, most often via an airport (rather than a seaport or a land port of entry).

These border crossers traveled to the United States from countries all over the world, with the most frequent regions of origin being Europe and Central and South America. Almost all were male (86.6 percent), and a large majority was married (82 percent). The average age of the indictees at the time of their border crossing was 31-years-old. Eleven percent were known to be previously arrested in the United States, and 11 percent were known to be previously arrested abroad.

"The events of September 11, 2001, demonstrated in stark relief the destruction that can be associated with individuals who cross in and out of the country," said Kathleen Smarick, START researcher and co-author of the report.

"This project sought to determine to what degree U.S. ports of entry can be key points for intercepting individuals who seek to launch such attacks. These data and analyses reveal no clear patterns of border-crossing behavior among those with terrorist intentions."

The researchers found that 87 percent of the known border crossings attempted by these federal terrorism indictees were successful, allowing the individuals to enter or exit the United States. The type of port of entry used by a traveler was not significantly related to the likely success of the crossing.

Closer examination of selected cases of border crossings by those who intended to engage in terrorism against the United States revealed that, among the non-U.S. citizens who entered the country, several relied upon political asylum mechanisms to legally enter and remain in the United States.

Fake and fraudulent documentation also played a key role in allowing these terrorist conspirators to gain access to the country. Working with the National Center for Border Security and Immigration (BORDERS), the research team also conducted analyses of the screening processes used at ports of entry and whether the screening process could be adapted. The report aims to provide an empirically grounded baseline understanding of the border-crossing behaviors of individuals who have engaged in or have planned involvement in terrorist activity directed against the United States and, as such, help inform border screening processes.

To download the full report, "Border Crossings and Terrorist Attacks in the United States: Lessons for Protecting against Dangerous Entrants," click here.

The report's appendices can be found here. The project was funded through START by the U.S. Department of Homeland Security Science & Technology Directorate Office of University Programs.