It is a major concern often heard from US border residents: how much might increasing drug cartel violence in Mexico “spill over” into the United States? It’s certainly true that illicit markets – in drugs, guns and people – have long flourished across the 2,000 mile frontier, and pose policy concerns for both countries. To date, the major strategy to tackle this problem has been a law enforcement approach sponsored by the United States. Is this the right approach? CGD’s Beyond the Fence Study Group is dedicated to investigating the ripple effects of policy decisions on one side of the border, in hopes of moving beyond the unilateral, domestic law enforcement that dominates the current policy approach.

Those fears of “spill over” violence into the United States, while not unfounded, have caused widespread paranoia: cited as fact, dramatized on National Geographic’s "Border Wars," and leveraged to inspire fringe websites. Military veterans residing in the border have created private militias (such as the Arizona Border Recon) to take matters into their own hands, arguing that the US government has failed in its duty to adequately protect the border.

However, the data show a different picture. Despite geographic adjacency to some of the most violent cities in the world and growing links between US gangs and Mexican cartels, the US side of the border has experienced a remarkably low (and declining) homicide rate since at least 1990. For US residents, the bloodshed has remained beyond the fence.

Violence in the Borderlands

To investigate trends in border violence, we compiled data from the Instituto Nacional de Estadística y Geografía, the Consejo Nacional de Población, the Federal Bureau of Investigation Uniform Crime Reporting Statistics, the New Mexico Department of Public Safety, the Texas Department of Public Safety, and the US Census Bureau intercensal population estimates.

The map below illustrates the striking disparity between homicide rates on each side of the border. In 2012 (the most recent year available for all locations), Mexican border municipalities experienced 34.5 murders for every 100,000 people.  By contrast, the homicide rate in US border counties was only 1.4, far below the US national average (4.7), and a tiny fraction of that experienced by their Southern neighbors.

Homicide Rates in the US–Mexico Borderlands, 2012

While almost half of the Mexican municipalities along the border experienced more than 40 murders per 100,000 people in 2012 (176 in Tamaulipas’ Ciudad Mier), the highest homicide rate in the US border counties was 12.9 (Yuma, AZ). The next most violent county experienced only 5.4 murders per 100,000 people. Notably, some of the safest locations in the United States are contiguous to many of the most dangerous places in Mexico. Most striking is the contrast between Ciudad Juárez and El Paso, two large cities that constitute a binational metropolitan area. Once called “the murder capital of the world,” Mexico’s Ciudad Juárez is only 300 feet from El Paso, “America’s safest city.” In 2012, Ciudad Juárez had 58 homicides per 100,000 people, while El Paso experienced fewer than one (0.6).

Trends over Time

Are the 2012 rates just a fluke? The short answer is no; in fact, the disparity in violence levels was most pronounced in 2010, at the height of Mexico’s drug war. The graph below depicts annual homicide rates in Mexican border municipalities and US border counties from 1990 to 2012. The Mexican side of the border has always been more violent, with murder rates fluctuating between 15 and 20 homicides per 100,000 people until the mid-2000s. However, between 2007 and 2010, the murder rate in Mexico’s border municipalities spiked drastically, increasing seven-fold. This sudden widespread violence coincided with violent territorial contestation among drug cartels and the Mexican government’s militarized response. The significant drop in homicides after 2010, largely explained by improved security in Ciudad Juárez, does not diminish the fact that violence in northern Mexico remains high.

Homicide Rates in  the US–Mexico Borderlands, 1990-2012

On the other hand, US homicide rates have remained consistently low. The homicide rate in counties bordering Mexico has not only been negligible over the past two decades (especially when compared to the US national average), but has actually slightly declined since 1990. Even in the face of drug trafficking bloodshed across the Rio Grande, US border counties exhibit a surprisingly low level of lethal violence. We hope these data will feed into the policy discussion.