|(15 Aug 2023)
Remarkable Variation by Sector and Nationality
The Southwest Border is often represented as a single, uniform line separating the United States and
Mexico. But at nearly 2,000 miles, touching four U.S. states and six Mexican states, and crossing
multiple terrains and ecosystems, this representation of the border can obscure the
geographically-specific trends in the number and nationality of migrants arrested by Border Patrol in
each of the agency’s nine sectors.
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.
TRAC is a self-supporting, nonpartisan, and independent research organization specializing in
data collection and analysis on federal enforcement, staffing, and spending. We produce multiple
reports every month on critical issues, and we also provide comprehensive data analysis tools.
To know more about our work, click