Boise wasn't Garcia-Langarica's for long either. One of his former drivers became a competing crew boss. Still, "they were not shooting each other in the street," Ruplinger said. "They'd know each other. It was just a job. I kept realizing that this is huge."
In Portland, black-tar heroin had been dealt on downtown streets by Hondurans or Guatemalans -- until the late 1990s. Then, police noticed that new dealers, all from Nayarit, were making deliveries by car all over the city.
In 1999, Multnomah County Health Department workers, examining coroner's reports, found that deaths from black-tar heroin overdoses had more than doubled since 1996, to more than 100 a year. An ad campaign urging junkies not to shoot up alone helped drive down that figure, although lately it has crept back to the levels of the late '90s.
In Portland and elsewhere, competition among Xalisco dealers and the resulting lower prices changed the nature of the heroin trade. No longer were burglaries and holdups the measure of a city's heroin problem. Junkies could maintain their habits cheaply. A spike in overdoses was the mark of black-tar heroin's arrival.
"The classic picture of a heroin addict is someone who steals," said Gary Oxman, a Multnomah County Health Department doctor who conducted the study of overdoses. "That disappears when you have low-cost heroin. You could maintain a moderate heroin habit for about the same price as a six-pack of premium beer."
It was the same in other cities where Xalisco dealers settled. In Denver, addicts say the cost of a dose of black tar has dropped as low as $8.
In the Utah County suburbs of Salt Lake City, it was more than $50 a dose in the early 1990s.
"Now we're seeing it for $10 to $15 per balloon," said Bruce Chandler, program services manager for the county's Foothill Treatment Center.
Until the late 1990s, Mexican black-tar heroin was available only west of the Mississippi. To the east, Colombian powder heroin predominated.
But over the last decade, production of Mexican heroin has climbed rapidly, reaching an estimated 18 metric tons in 2007, while Colombian output has dropped, partly because of U.S.-funded efforts to eradicate Colombian poppy fields, according to the 2009 National Drug Threat Assessment issued by the U.S. Justice Department.
As a result, "Mexican criminal groups are expanding Mexican heroin distribution in eastern states, where previously only South American heroin had been available," the report said. Estimates of Mexican and Colombian heroin production in the report suggest that black tar now accounts for two-thirds or more of the U.S. heroin market.
According to narcotics agents and former dealers, Xalisco immigrants drove black tar's eastward expansion, moving into Columbus and from there to parts of rural Ohio and Pennsylvania and to Nashville and Charlotte.
In many of these places, heroin had been rare. Addicts more commonly used prescription pain pills.
Black tar is cheaper than pain medications. Xalisco dealers exploited that advantage and pushed relentlessly for new customers. Addicts in Columbus say they offered rewards for referrals to new users: eight or 10 free balloons of heroin for every $1,000 in sales an addict brought in.
Typical of these heroin entrepreneurs was a youth who called himself Manny Munoz-Lopez. He began as a driver in Columbus and rose to become a cell leader when others sold their networks and returned to Mexico.
In 2006, he expanded to the suburbs of Pittsburgh, where police say he took the name Julio Ramirez. Prosecutors say he recruited junkies at methadone clinics to be salesmen as well as customers.
Gary Palacios, now serving a prison term in Pennsylvania for selling heroin, said he became Ramirez's wholesaler for north Pittsburgh. Ramirez shook up the local market, he said. Before, dealers waited for users to come to them. Ramirez's drivers actively sought out customers. For every 20 balloons an addict bought, Ramirez gave five free ones, Palacios said.