MEXICAN DRUG CARTEL VIOLENCE SPILLS OVER, ALARMING U.S.

TUCSON - Sgt. David Azuelo stepped gingerly over the specks of blood
on the floor, took note of the bullet hole through the bedroom
skylight, raised an eyebrow at the lack of furniture in the
ranch-style house and turned to his squad of detectives investigating
one of the latest home invasions in this southern Arizona city.

A 21-year-old man had been pistol-whipped throughout the house, the
gun discharging at one point, as the attackers demanded money, the
victim reported. His wife had been bathing their 3-month-old son when
the intruders arrived.

"At least they didn't put the gun in the baby's mouth like we've seen
before," Sergeant Azuelo said. That same afternoon this month, his
squad was called to the scene of another home invasion, one involving
the abduction of a 14-year-old boy.

This city, an hour's drive north of the Mexican border, is coping
with a wave of drug crime the police suspect is tied to the bloody
battles between Mexico's drug cartels and the efforts to stamp them out.

Since officials here formed a special squad last year to deal with
home invasions, they have counted more than 200 of them, with more
than three-quarters linked to the drug trade. In one case, the
intruders burst into the wrong house, shooting and injuring a woman
watching television on her couch. In another, in a nearby suburb, a
man the police described as a drug dealer was taken from his home at
gunpoint and is still missing.

Tucson is hardly alone in feeling the impact of Mexico's drug cartels
and their trade. In the past few years, the cartels and other drug
trafficking organizations have extended their reach across the United
States and into Canada. Law enforcement authorities say they believe
traffickers distributing the cartels' marijuana, cocaine, heroin,
methamphetamine and other drugs are responsible for a rash of
shootings in Vancouver, British Columbia, kidnappings in Phoenix,
brutal assaults in Birmingham, Ala., and much more.

United States law enforcement officials have identified 230 cities,
including Anchorage, Atlanta, Boston and Billings, Mont., where
Mexican cartels and their affiliates "maintain drug distribution
networks or supply drugs to distributors," as a Justice Department
report put it in December. The figure rose from 100 cities reported
three years earlier, though Justice Department officials said that
may be because of better data collection methods as well as the
spread of the organizations.

Gov. Rick Perry of Texas has asked for National Guard troops at the
border. The Obama administration is completing plans to add federal
agents along the border, a senior White House official said, but does
not anticipate deploying soldiers.

The official said enhanced security measures would include increased
use of equipment at the ports of entry to detect weapons carried in
cars crossing into Mexico from the United States, and more
collaboration with Mexican law enforcement officers to trace weapons
seized from crime scenes.

Law enforcement officials on both sides of the border agree that the
United States is the source for most of the guns used in the violent
drug cartel war in Mexico.

"The key thing is to keep improving on our interdiction of the
weapons before they even get in there," said Janet Napolitano, the
secretary of homeland security and the former governor of Arizona,
who will be testifying before Congress on Wednesday.

Familiar Signs

Sergeant Azuelo quickly began to suspect that the pistol whipping he
was investigating was linked to a drug dispute. Within minutes, his
detectives had found a blood-spattered scale, marijuana buds and
leaves and a bundle of cellophane wrap used in packing marijuana.

Most often, police officials say, the invasions result from an unpaid
debt, sometimes involving as little as a few thousand dollars. But
simple greed can be at work, too: one set of criminals learns of a
drug load, then "rips" it and sells it.

"The amount of violence has drastically increased in the last 6 to 12
months, especially in the area of home invasions, " said Lt. Michael
O'Connor of the Pima County Sheriff's Department here. "The people we
have arrested, a high percentage are from Mexico."

The violence in the United States does not compare with what is
happening in Mexico, where the cartels have been thriving for years.
Forbes recently listed one of Mexico's most notorious kingpins,
Joaquin Guzman, on its list of the world's billionaires. (No. 701,
out of 793, with a fortune worth $1 billion, the magazine said.)

But a crackdown begun more than two years ago by President Felipe
Calderon, coupled with feuds over turf and control of the
organizations, has set off an unprecedented wave of killings in
Mexico. More than 7,000 people, most of them connected to the drug
trade or law enforcement, have died since January 2008. Many of the
victims were tortured. Beheadings have become common.

At times, the police have been overwhelmed by the sheer firepower in
the hands of drug traffickers, who have armed themselves with assault
rifles and even grenades.

Although overall violent crime has dropped in several cities on or
near the border - Tucson is an exception, reporting a rise in
homicides and other serious crime last year - Arizona appears to be
bearing the brunt of smuggling-related violence. Some 60 percent of
illicit drugs found in the United States - principally cocaine,
marijuana and methamphetamine - entered through the border in this state.

The city's home-invasion squad, a sergeant and five detectives
working nearly around the clock, was organized in April. Phoenix
assembled a similar unit in September to investigate kidnappings
related to drug and human smuggling. In the last two years, the city
has recorded some 700 cases, some involving people held against their
will in stash houses and others abducted.

The state police also have a new human-smuggling squad that focuses
on the proliferation of drop houses, where migrants are kept and
often beaten and raped until they pay ever-escalating smuggling fees.

"Five years ago a home invasion was almost unheard of," said
Assistant Chief Roberto Villasenor of the Tucson Police Department.
"It was rare."

Web of Crime

Tying the street-level violence in the United States to the cartels
is difficult, law enforcement experts say, because the cartels
typically distribute their illicit goods through a murky network of
regional and local cells made up of Mexican immigrants and United
States citizens who send cash and guns to Mexico through an elaborate chain.

The cartels "may have 10 cells in Chicago, and they may not even know
each other," said Michael Braun, a former chief of operations for the
Drug Enforcement Administration.

Elizabeth W. Kempshall, who is in charge of the drug agency's office
in Phoenix, said the kind of open warfare in some Mexican border
towns - where some Mexican soldiers patrol in masks so they will not
be recognized later - has not spilled over into the United States in
part because the cartels do not want to risk a response from law
enforcement here that would disrupt their business.

But Mrs. Kempshall and other experts said the havoc on the Mexican
side of the border might be having an impact on the drug trade here,
contributing to "trafficker on trafficker" violence.

For one thing, they say, the war on the Mexican side and the new
border enforcement are disrupting the flow of illicit drugs arriving
in the United States. The price of cocaine, for instance, a barometer
of sorts for the supply available, has surged.

With drugs in tighter supply, drug bosses here and in Mexico take a
much harder line when debts are owed or drugs are stolen or
confiscated, D.E.A. officials said.

Although much of the violence is against people involved in the drug
trade, law enforcement authorities said such crime should not be
viewed as a "self-cleaning oven," as one investigator put it, because
of the danger it poses to the innocent. It has also put a strain on
local departments.

Several hours after Sergeant Azuelo investigated the home invasion
involving the pistol whipping, his squad was called to one blocks away.

This time, the intruders ransacked the house before taking a
14-year-old boy captive. Gang investigators recognized the house as
having a previous association with a street gang suspected of
involvement in drug dealing.

The invaders demanded drugs and $10,000, and took the boy to make
their point. He was released within the hour, though the family told
investigators it had not paid a ransom.

"You don't know anybody who is going to pay that money?" the boy said
his abductors kept asking him.

The boy, showing the nonchalance of his age, shrugged off his ordeal.

"No, I'm not scared," he said after being questioned by detectives,
who asked that his name not be used because the investigation was continuing.

Growing Networks

Not all the problems are along the border.

The Atlanta area, long a transportation hub for legitimate commerce,
has emerged as a new staging ground for drug traffickers taking
advantage of its web of freeways and blending in with the wave of
Mexican immigrants who have flocked to work there in the past decade.

Last August, in one of the grislier cases in the South, the police in
Shelby County, Ala., just outside Birmingham, found the bodies of
five men with their throats cut. It is believed they were killed over
a $450,000 debt owed to another drug trafficking faction in Atlanta.

The spread of the Mexican cartels, longtime distributors of
marijuana, has coincided with their taking over cocaine distribution
from Colombian cartels. Those cartels suffered setbacks when American
authorities curtailed their trading routes through the Caribbean and
South Florida.

Since then, the Colombians have forged alliances with Mexican cartels
to move cocaine, which is still largely produced in South America,
through Mexico and into the United States.

The Mexicans have also taken over much of the methamphetamine
business, producing the drug in "super labs" in Mexico. The number of
labs in the United States has been on the decline.

While the cartel networks have spread across the United States, the
border areas remain the most worrisome. At the scene of the
pistol-whipping here, Sergeant Azuelo and his team methodically investigated.

Their suspicions grew as they walked through the house and noticed
things that seemed familiar to them from stash houses they had
encountered: a large back room whose size and proximity to an alley
seemed well-suited to bundling marijuana, the wife of the victim
reporting that they had no bank accounts and dealt with everything in
cash, the victim's father saying over and over that his son was "no
saint" and describing his son's addiction problems with prescription drugs.

A digital scale with blood on it was found in a truck bed on the
driveway, raising suspicion among the detectives that the victim was
trying to hide it.

The house, the wife told them, had been invaded about a month ago,
but the attackers left empty-handed. She did not call the police
then, she said, because nothing was taken.

Finally, they saw the cellophane wrap and drug paraphernalia and
obtained a search warrant to go through the house more meticulously.

The attackers "were not very sophisticated," Sergeant Azuelo said,
but they somehow knew what might be in the house. "For me, the
question is how much they got away with," he said. "The family may never tell."

All in all, Sergeant Azuelo said, it was a run-of-the-mill call in a
week that would include at least three other such robberies.

"I think this is the tip of the iceberg," Detective Kris Bollingmo
said as he shined a light through the garage. "The problem is only
going to get worse."

"We are," Sergeant Azuelo added, "keeping the finger in the dike."