This report examines nearly fifteen years of data on Border Patrol arrests to emphasize two significant trends that shape how the public understands the border and border enforcement. First, whereas the San Diego and Tucson sectors fifteen years ago were the busiest sectors for Border Patrol arrests, these two sectors have been largely supplanted by sectors in Texas as well as the relatively narrow Yuma sector in terms of percent of arrests—suggesting, in part, a significant shift in where migrants are crossing.

Between 2008 and 2010, for instance, arrests in the Tucson sector alone made up about 45 percent of the total arrests along the border while arrests in the San Diego sector made up another 15 to 23 percent. After 2010, however, the Rio Grande Valley (RGV) sector quickly overtook San Diego and Tucson, to over half of all Border Patrol arrests along the Southwest border by 2014 and remained the sector with the most arrests as of July 2022. Del Rio, also in southern Texas, and Yuma, the narrowest sector, have also raced to second and third place with 21.1 percent and 15.5 percent respectively.

Second, although the historical framework for immigration enforcement along the Southwest Border was geared towards Mexican nationals, the past decade has seen considerable diversification of who Border Patrol is encountering, beginning with Central American migrants and expanding recently to even more nationalities throughout Latin America, the Caribbean, and beyond.

As late as FY 2013, Mexican nationals made up the largest group of arrests. However, since 2012, migrants from Guatemala, Honduras, and El Salvador—three countries often referred to collectively as the Northern Triangle countries—increased steadily and overtook Mexican nationals as the group with the most arrests. What is even more remarkable than the recent overall increase in Border Patrol arrests is the number of arrests of migrants who were from beyond Mexico or the Northern Triangle countries. Fiscal year 2021 saw a dramatic increase in the number of these migrants, which grew from just 7,777 in FY 2011 to over a third of a million arrests (367,275) in FY 2021. These numbers increased again to 728,742 arrests in FY 2022, marking the first year that non-Mexican and non-Northern Triangle nationalities outpaced the other two.

As the data on Border Patrol arrests in this report show, not only has the breakdown in total border arrests varied remarkably over the past decade, but the composition by nationality has also changed dramatically—and changed in a way that is reflected in geographically specific ways along the length of the U.S.-Mexico border. Because these data only go through July 2022, this report does not reflect changes that have occurred in the past year. However, this report lays the groundwork for recognizing sector-by-sector trends in total arrests and the nationality of those arrests going forward. Detailed data on Border Patrol arrests can be found at TRAC’s online Border Patrol Arrest tool here.