But here in Mexicali, people fear the desert sun more than drug hit men. The city of 700,000 has a homicide rate comparable to that of Wichita, Kan., and one of the biggest police deployments is Operation Beat the Heat, in which officers haul blocks of ice to shantytown residents.
There hasn't been a bank robbery in Mexicali in 18 months, or a reported kidnapping in a year. Mexicali is considered so safe that top law enforcement officials from Tijuana raise their families here, and are seen visiting restaurants and movie theaters without the phalanx of bodyguards that usually follows them everywhere else.
But is Mexicali an oasis of tranquillity, or just a mirage?
Across the border in California's Imperial County, U.S. authorities believe the Baja California state capital has become the major staging ground for drug trafficking into the U.S. The Calexico port of entry now leads the nation in cocaine seizures, with a 64% increase in overall drug seizures for the period from October 2008 through July 2009 compared with the same period a year earlier, according to U.S. Customs and Border Protection.
U.S. law enforcement agencies have dismantled at least half a dozen trafficking operations since 2007, each of them a key link in a pipeline pumping tons of cocaine, methamphetamine and other drugs to cities across the U.S.
Some U.S. authorities suspect that the fire-free zone in Mexicali comes at a cost: a cozy relationship between Mexican law enforcement and the country's most powerful organized crime group, the Sinaloa drug cartel, which is believed to have shifted trafficking through the city to avoid gang battles in other border areas.
"We should be seeing huge numbers of narcotic arrests and seizures. . . . I don't see it," said Ernie Limon, a supervisor with the California Bureau of Narcotic Enforcement. "They don't have a lot of law enforcement presence or commitment."
Mexican authorities deny any relationship exists, saying the calm indicates that major traffickers have been driven out of the city. Mexicali's director of public security, Alonso Mendez, who oversees the 1,800-member municipal police force, said authorities arrest organized crime members from Sinaloa before they get established.
Indeed, the city of wide, treeless boulevards offers little evidence of narco-extravagance or violence. Mexicali's conservative population of civil servants and agricultural laborers has tended to frown on ostentatious displays of wealth. Outsized mansions are few. And narco-culture staples such as roadside "death saint" shrines haven't spread here, as they have in Tijuana and Nuevo Laredo.
"It's not easy for [organized crime groups] to take root here," said Mendez, a young, burly former narcotics intelligence officer. A corrupt police department, he added, would create dysfunction and upheaval, the exact opposite of the current situation. "We'd be seeing cops dying and fighting and being arrested, and we're not," Mendez said.
Officials in Mexico and the U.S. have suspected government ties to the Sinaloa cartel since a videotaped confession of a cartel gunman surfaced two years ago, alleging that former state Atty. Gen. Antonio Martinez Luna was taking payoffs. Martinez Luna has vehemently denied the accusation.
A federal police commander and one of his officers pleaded no contest this year to drug-related charges after being arrested in a West Covina home where police seized $630,000 in alleged drug proceeds.
The federal government, which leads anti-drug efforts in Mexico, has only about 20 agents in Mexicali, which in itself has raised eyebrows among U.S. law enforcement officials.
But some Mexican authorities say the U.S. is partly to blame for not improving its border defenses in adjacent Calexico, the third-busiest U.S.-Mexico port of entry, which handles about 40,000 pedestrian and car crossings daily. U.S. authorities acknowledge that the 35-year-old facility doesn't meet modern security standards. One recent undercover investigation suggests that U.S. inspectors may be stopping as few as one in 40 shipments through the 10-lane crossing.
Traffickers have boasted publicly about how easy it is to slip drugs into Imperial County. "I was great at it. I had never lost a car in the border. [Drug-sniffing] dogs never hit it or nothing," convicted smuggler Carlos Cuevas Jr., the leader of a large trafficking organization, testified last year.
The layout of the Calexico port offers an advantage to smugglers. The facility sits only about 30 yards across the U.S.-Mexico line, giving canine units limited space, and limited time, to conduct preliminary checks before vehicles reach the inspection booths. And the cramped secondary inspection area provides little room to use the mobile gamma ray machines that can penetrate steel and help detect contraband. Newer facilities lie farther inside U.S. territory.
"There are lots of infrastructure constraints," said Billy Whitford, the port director. "The small footprint limits our ability to conduct our border security mission."
Those obstacles were illustrated in a recent California state investigation in which an undercover officer penetrated a Mexicali-based ring. The eight-month probe revealed that traffickers sent about 40 loads across the border. Inspectors detected only one of them, according to Limon, the California Bureau of Narcotic Enforcement supervisor.
Beyond the border crossing, smugglers face relatively few obstacles. Unlike in San Diego, where they must run a gantlet of local law enforcement, only a handful of Calexico cops and Imperial County sheriff's deputies patrol downtown streets, including Imperial Avenue, the north-south thoroughfare leading to Interstate 8.
Drug enforcement duties have fallen to a task force operating at a bunker-like compound in nearby Imperial. Several wiretap probes, among the largest undertaken in recent years by the Drug Enforcement Administration, have exposed the Sinaloa cartel's vast distribution network sprouting from the Calexico crossing.
A 2007 case against a Mexicali-based ring resulted in the arrest of more than 400 people in the U.S. Two years later, more than 700 suspects from Los Angeles to Maine were linked to six distribution organizations in Mexicali.
The trafficking rings seem to regenerate quickly. So far this year, the California Bureau of Narcotic Enforcement has filed indictments against two more Mexicali-based organizations, and several investigations are underway.
That's no surprise to Calexico Police Chief James Lee Neujahr, who has seen his city of about 30,000 turn into a stash-house haven and recruiting center for smuggling groups needing drivers to move drugs across the border.
Standing at the palm-lined gateway to the city, the chief pointed to the "Welcome to Calexico" sign at Friendship Park, where cartel lookouts report on the progress of drug shipments coming through the crossing at 1st and Paulin streets.
A steady stream of northbound cars turned onto downtown streets, including one driven by a middle-aged woman. "She could have 200 pounds of dope," he said. "You can't stop and search every car."
Neujahr believes smuggling groups long ago figured out that Imperial County lacks resources, a neglected status reaffirmed this year, he said, when the Justice Department issued $8.7 million in Southwest border crime grants. Communities as far away as San Mateo County in the Bay Area got funding, but not Imperial County.
"This is kind of a no-man's land," Neujahr said. "Until [drugs] get farther up the road, nobody deals with it."