A new Drug Enforcement Administration (DEA) report said the majority of heroin seized by US authorities in 2012 was sourced to South America, a somewhat surprising statistic that may point to a disturbing reality: the US is running blind when it comes to understanding the increasingly potent and lucrative heroin networks.

According to the 2014 DEA National Drug Threat Assessment (pdf) released in late November, slightly more than half of all heroin seized in the United States in 2012 originated in South America, while Mexico accounted for 45 percent.

The data continues a long-term trend. The DEA says South America has consistently supplied the United States with the majority of the country's heroin since the mid-1990s, with 2011 serving as the only exception.

This article was first published by InSight Crime. You can read the original here.

These numbers are surprising because Mexican heroin production is thought to be so much higher than Colombia's, the source of most of South America's heroin. According to the 2013 annual World Drug Report (pdf) by the United Nations Office on Drugs and Crime (UNODC), Mexico's potential heroin production in 2012 -- the same year tracked by the DEA report -- was 30 times higher than Colombia's.

"While acknowledging the growing importance of Mexico as a supply country for heroin reaching its market," the UNODC writes, "the United States -- on the basis of information from its Heroin Signature Program -- continues to consider Colombia the primary source of heroin in the country."

The numbers become even more confusing when we look at the DEA's own data. The DEA chart (see below) reflects the increasing availability of Mexican-sourced heroin in the US market over the last 10 years. The 2012 figure marks a sharp increase from 2003, when less than 5 percent of all heroin seized came from the US' southern neighbor.

Mexico's growing role as supplier of heroin for US markets is even more evident when examining geographical seizure trends (see graph below). Annual heroin seizures in the United States rose roughly 90 percent over a recent five year period, from 2,500 kilos in 2009 to approximately 4,750 kilos in 2013.

Meanwhile, the amount of heroin seized along the US southwest border jumped about 150 percent over that same time frame, indicating Mexico is likely fueling the apparent increased availability of the illicit drug in the United States.

Yet, the agency insists, South America's heroin is what they find on the US streets.

InSight Crime Analysis

Since the DEA's report does not seek to establish the reasons why there is a discrepancy between the ratio of the estimated amount produced in Mexico and Colombia (30:1), and the amount seized in the United States (roughly 1:1), InSight Crime offers a few possibilities:

(1) The US has far deeper sources and intelligence on the movement of opiates from Colombia to the United States. This would help law enforcement track and seize Colombia-sourced heroin at a higher rate than Mexico-sourced heroin. The prospect is disturbing, largely because official statements would indicate that the US is saturated with Mexican heroin, and US officials have been reporting since at least the 2011 Drug Threat Assessment (pdf) a drop in seizures of Colombia-sourced heroin.

One Chicago policeman, who wished to remain anonymous because he is not authorized to speak on the record, told InSight Crime the incongruous data may have something to do with how much trust there is between the US and Colombian authorities, and how little trust there is between US and Mexican authorities.

"We have forged such a strong relationship with Colombia that I think we know most of the unknowns in Colombia," the policeman surmised of skewed ratio. "We don't have that relationship with Mexico because the government is a facade for the cartels."

The result, he said, is that the police do not know the source of the heroin for the street gangs they are tracking in that city, which is considered a primary distribution point for Mexican drug cartels.

2) Colombia's heroin production is much higher than has been reported. In its 2013 report on illicit crop cultivation (pdf), the United Nations Office on Drugs and Crime (UNODC) said that -- despite data indicating that Colombia's poppy production had been declining since 1998 -- heroin prices remained unchanged.

"Nominal prices for heroin at the wholesale level were lower in 2011 in both dollars and Colombian pesos, than they were five years before, suggesting that the supply of heroin did not drastically diminish," the report said.

Gathering data on illicit crop production is an inexact science. Street price may be a better indicator of availability and production levels. In this respect, the DEA offers some more contradictory data. According to the DEA's Heroin Domestic Monitor Program (pdf), the price of South American heroin dropped 57 cents from 2010 to 2011, the same period in which the agency's other measure, the Heroin Signature Program, said Colombia's supply continued its steady decline. (Mexico-sourced heroin dropped 65 cents in same period.)

"It is unclear how Colombia, given its much lower potential production, could supply larger amounts to the United States market than Mexico," the UNODC 2013 report states. "This points to heroin production in Colombia having a greater degree of importance than that reflected in the available potential production estimates."

3) Mexican organizations are using Colombian techniques and chemists to produce white heroin. Mexican heroin is traditionally brown or a dark tar-like substance; Colombia's is white. However, since 2011, US investigators have said this may be outdated.

"Investigative reporting suggests that heroin producers in Mexico may be using Colombian processing techniques to create a white powder form of heroin," the 2011 Drug Threat Assessment report (pdf) reads. "However, signature analysis has not confirmed the existence of this form of heroin. If true, this development likely portends intent on the part of Mexican TCOs to further expand into US. white powder heroin markets."

This is a logical progression. Mexican criminal groups are the key distributors of Colombia-sourced cocaine. They have been learning from and employing Colombians for decades. Colombian heroin also has a higher purity making it a more lucrative product.

4) The DEA methodology is flawed. The DEA uses what it calls the Heroin Signature Program (HSP), which is based on a limited sampling of seizures made at the country's ports of entry, and the Heroin Domestic Monitor Program (HDMP) to trace the source of the heroin seized in the US.

In 2010 and 2011, the last years public data was made available on the HSP process (pdf), the samples totaled between 1 and 1.5 tons of heroin. The HDMP is based on a sampling from 27 cities, which include between 600 and 800 total samples purchased on the streets.

Complaints about the DEA's methodology stretch back to at least 2002 when the Government Accounting Office said the two methodologies were "based on non-representative samples of their respective populations."

What's more, the samples collected by the DEA at ports of entry are only about five percent of the estimated total consumed in the United States (see the UN's World Drug Report 2010 - pdf).

Other US agencies, perhaps faced with the same discrepancies, also offer contradictory conclusions. On its webpage, the Office of National Drug Control Policy states, "Opium poppy cultivation in Mexico remains high, and Mexico continues as the primary supplier of heroin to the United States."