Southwest Border Violence: Issues in Identifying and Measuring Spillover Violence

Jennifer E. Lake, Coordinator
Analyst in Domestic Security

Kristin M. Finklea, Coordinator
Analyst in Domestic Security

Mark Eddy
Specialist in Social Policy

Celinda Franco
Specialist in Crime Policy

Chad C. Haddal
Analyst in Immigration Policy

William J. Krouse
Specialist in Domestic Security and Crime Policy

Mark A. Randol
Specialist in Domestic Intelligence and Counter-Terrorism

There has been a recent increase in the level of drug trafficking-related violence within and between the drug trafficking organizations in Mexico. This violence has generated concern among U.S. policy makers that the violence in Mexico might spill over into the United States. Currently, U.S. federal officials deny that the recent increase in drug trafficking-related violence in Mexico has resulted in a spillover into the United States, but they acknowledge that the prospect is a serious concern. 

The most recent threat assessment indicates that the Mexican drug trafficking organizations pose the greatest drug trafficking threat to the United States, and this threat is driven partly by U.S. demand for drugs. Mexican drug trafficking organizations are the major suppliers and key producers of most illegal drugs smuggled into the United States across the Southwest border (SWB). The nature of the conflict between the Mexican drug trafficking organizations in Mexico has manifested itself, in part, as a struggle for control of these smuggling routes into the United States. Further, in an illegal marketplace—such as that of illicit drugs—where prices and profits are elevated due to the risks of operating outside the law, violence or the threat of violence becomes the primary means for settling disputes. 

When assessing the potential implications of the increased violence in Mexico, one of the central concerns for Congress is the potential for what has been termed "spillover" violence—an increase in drug trafficking-related violence in United States. While the interagency community has defined spillover violence as violence targeted primarily at civilians and government entities— excluding trafficker-on-trafficker violence—other experts and scholars have recognized trafficker-on-trafficker violence as central to spillover. When defining and analyzing changes in drug trafficking-related violence within the United States to determine whether there has been (or may be in the future) any spillover violence, critical elements include who may be implicated in the violence (both perpetrators and victims), what type of violence may arise, when violence may appear, and where violence may occur (both along the SWB and in the nation's interior). 

Currently, no comprehensive, publicly available data exist that can definitively answer the question of whether there has been a significant spillover of drug trafficking-related violence into the United States. Although anecdotal reports have been mixed, U.S. government officials maintain that there has not yet been a significant spillover. In an examination of data that could provide insight into whether there has been a significant spillover in drug trafficking-related violence from Mexico into the United States, CRS analyzed violent crime data from the Federal Bureau of Investigation's Uniform Crime Report program. The data, however, do not allow analysts to determine what proportion of the violent crime rate is related to drug trafficking or, even more specifically, what proportion of drug trafficking-related violent crimes can be attributed to spillover violence. In conclusion, because the trends in the overall violent crime rate may not be indicative of trends in drug trafficking-related violent crimes, CRS is unable to draw definitive claims about trends in drug trafficking-related violence spilling over from Mexico into the United States. 

This report will be updated as circumstances warrant. 


Date of Report: January 28, 2010
Number of Pages: 37
Order Number: RS22855
Price: $29.95