shocking brutality spills over into u.s.

AP | Just as government officials had feared, the drug violence raging in Mexico is spilling over into the United States.

U.S. authorities are reporting a spike in killings, kidnappings and home invasions connected to Mexico's murderous cartels. And to some policymakers' surprise, much of the violence is happening not in towns along the border, where it was assumed the bloodshed would spread, but a considerable distance away, in places such as Phoenix and Atlanta.

Investigators fear the violence could erupt elsewhere around the country because the Mexican cartels are believed to have set up drug-dealing operations all over the U.S., in such far-flung places as Anchorage, Alaska; Boston; and Sioux Falls, S.D.

"The violence follows the drugs," said David Cuthbertson, agent in charge of the FBI's office in the border city of El Paso, Texas.

The violence takes many forms: Drug customers who owe money are kidnapped until they pay up. Cartel employees who don't deliver the goods or turn over the profits are disciplined through beatings, kidnappings or worse. And drug smugglers kidnap illegal immigrants in clashes with human smugglers over the use of secret routes from Mexico.

So far, the violence is nowhere near as grisly as the mayhem in Mexico, which has witnessed beheadings, assassinations of police officers and soldiers, and mass killings in which the bodies were arranged to send a message. But law enforcement officials worry the violence on this side could escalate.