Another violent incident along the US side of the Mexican border has been attributed to Mexico’s criminal gangs and has again sparked concerns of “spillover violence” in that region. But the claim is not just false, but illogical.

The most recent case was a drug bust gone wrong that resulted in the death of a civilian law enforcement officer and left a police officer wounded in Texas last week in what local media described as a “Mexico-style” attack.

The operation, however, was intended to be a “textbook controlled delivery,” with a police informant posing as a truck driver delivering a large quantity of marijuana to Mexican drug traffickers at a designated meeting point, who was followed all the way by undercover police.

Before the truck could make its drop, it was attacked by gunmen in a convoy of sport-utility vehicles along a Texas highway. According to a press release from Harris County Sheriff’s Office: “Officers engaged in gunfire with the suspects” in an exchange that “resulted in the undercover officer being shot in the leg and the death of the occupant of the 18-wheeler.”

Police have so far arrested four men in relation to the attack, all believed to be Mexican nationals. The men have all allegedly admitted to having links with the notorious Zetas criminal syndicate.

[See InSight Crime’s Zetas profile]

“We are not going to tolerate these types of thugs out there using their weapons like the Wild, Wild West,” Drug Enforcement Administration (DEA) Houston Director Javier Peña told the Houston Chronicle.

The incident comes just weeks after Texas Attorney General Greg Abbott released a letter to the media he’d sent to President Barack Obama calling for stronger federal action to be taken to secure the border. Abbott wrote of the shooting of Hidalgo County Sheriff’s Office Deputy, Hugo Rodriguez, in a gun battle with a Gulf Cartel member, to demonstrate the growing menace of Mexican cartels.

[See InSight Crime’s Gulf Cartel profile]

The death of Rodriguez, Abbot wrote, was “not an isolated incident,” before proceeding to reel off a number of other violent incidents which he linked to Mexican gangs.

Politicians and officials in states across the US southern border have also warned of an invasion of Mexican gangs. In September, retired army generals Barry McCaffrey and Robert Scales delivered a report, sponsored by the Texas Department of Public Safety, warning of escalating violence on the Texas-Mexico border, describing in a rather dramatic fashion how the Texas side of the border has become a “war zone.”

According to McCaffrey, “The southwestern United States has become increasingly threatened by the spread of Latin American and Mexican cartel organized crime.”

Scales asserted that Mexican cartels are showing a clear intent to “move their operations into the United States.”

None of these assertions, however, are backed up by facts. In response to the McCaffrey report, the Austin American Statesman did the work that the politicians and military officials have not: retrieved the statistics. The Statesman’s analysis of all 14 Texan counties which share a border with Mexico shows that violent crime along the entirety of the Texas border actually fell by over 3 percent between 2006 and 2010. The combined number of murders in the 14 border counties fell over the same period by 33 percent.

The photograph to the right is a snapshot taken from the interactive map of the Statesman article. texas_crimeA closer look at the statistics is even more revealing. Some of the municipalities facing areas in Mexico most wraught with violence have seen drops in violent crime. Among these are El Paso, which saw murders fall from 17 in 2007 to 5 in 2010; Laredo, which saw a drop from 22 in 2006 to 9 in 2010; McCallen, which dropped from 9 in 2008 to 5 in 2010. Brownsville, meanwhile, maintained a steady murder rate and saw drops in every other crime statistic.

Authorities in Texas complained in the Statesman article of an increase in auto theft, which they related to the Mexican cartels using the cars to commit crimes in Mexico, but the statistics also do not back up the claims. El Paso, the area most affected by this crime, saw auto theft drop by half between 2006 and 2010.

Federal Bureau of Investigation statistics cited in a National Drug Intelligence Center (NDIC) report also cast doubt on whether there is significant “spillover” violence in the states bordering Mexico. Crime and violence in U.S. border communities decreased from 2009 to 2010 and assaults on U.S. border officials have also shown no increase, according to the report.

What’s more, as InSight Crime has reported, spillover violence is as much myth as it is reality, and numerous “incidents” are based on rumors, such as the supposed takeover of a ranch in Laredo and the Texas pipeline workers who were allegedly kidnapped and killed. Other cases are more clear cut, such as the October Hidalgo assault that killed the deputy, or the case of David Hartley, an innocent man shot dead by Mexican drug traffickers while jet skiing on a lake in southern Texas in September 2010.

But while Mexican criminal syndicates undoubtedly operate in the United States, these cases are not reflections of how they operate. To be sure, criminal gangs want to avoid conflict in the US as it is simply bad for business. The Zetas, Mexico’s bloodiest and least disciplined criminal syndicate, even issued a statement in recent days to this effect, which it posted in a public place in Nuevo Laredo, the city that faces the much safer city of Laredo, Texas. These cases, therefore, are outliers, illustrating that restraint, not aggression, is the operative word for large Mexican criminal gangs who wish to operate in the United States.