California, Arizona and Texas are dealing with murders and other problems related to Mexico's ongoing drug turf battles and the war between the Mexican government and drug cartels.

The Los Angeles Times reported Aug. 19 that Phoenix officials are investigating the execution-style deaths of 13 people who crossed the Mexican border; cartels also have hijacked vans carrying illegal workers and drugs on U.S. highways. Up to 100 illegal immigrants have been kidnapped in the Phoenix area and stashed in houses until their families paid ransom.

The post-9/11 law-enforcement buildup along the Mexican border has helped contain the violence in California, and more Border Patrol officers are being hired. But U.S. officials are increasingly worried about well-armed and experienced gunmen venturing north of the border. Both drugs and illegal immigration help fuel the violence.

"The smugglers are no longer mom-and-pop organizations. Now it's an industry," she Jennifer Allen, director of Border Action Network, an immigrants-rights' group. "So the violence increases. That's incredibly predictable." 

A Congressional report found that Mexican cartels were sending smugglers into the U.S. armed with assault rifles, grenades, bazookas, sniper scopes, and bulletproof vests. Teenage hitmen have been sent into Texas to kill on the orders of the cartels.