Wednesday's front-page story reported by James McKinley from Houston, "U.S. Stymied as Guns Flow to Mexican Cartels ," marked the third in a series about the drug trade on the U.S. border. Meanwhile, McKinley became at least the third Times journalist tolend support tothe liberal myth that 90 percent of guns used in drug crimes in Mexico come from the United States.
John Phillip Hernandez, a 24-year-old unemployed machinist who lived with his parents, walked into a giant sporting goods store here in July 2006, and plunked $2,600 in cash on a glass display counter. A few minutes later, Mr. Hernandez walked out with three military-style rifles.
One of those rifles was recovered seven months later in Acapulco, Mexico, where it had been used by drug cartelgunmen to attack the offices of the Guerrero State attorney general, court documents say. Four police officers and three secretaries were killed.
Although Mr. Hernandez was arrested last year as part of a gun-smuggling ring, most of the 22 others in the ring are still at large. Before their operation was discovered, the smugglers had transported what court documents described as at least 339 high-powered weapons to Mexico over a year and a half, federal agents said.
"There is no telling how long that group was operating before we caught on to them," said J. Dewey Webb, the agent in charge of the Houston division of theBureau of Alcohol, Tobacco, Firearms and Explosives.
Noting there are about 1,500 licensed gun dealers in the Houston area, Mr. Webb added, "You can come to Houston and go to a different gun store every day for several months and never alert any one."
The case highlights a major obstacle facing the United States as it tries to meet a demand from Mexico to curb the flow of arms from the states to drug cartels. The federal system for tracking gun sales, crafted over the years to avoid infringements on Second Amendment rights, makes it difficult to spot suspicious trends quickly and to identify people buying for smugglers, law enforcement officials say.
McKinley blamed light regulation in the United States, then pushed the "90 percent" figure.
Sending straw buyers into American stores, cartels have stocked up on semiautomatic AK-47 and AR-15 rifles, converting some to machine guns, investigators in both countries say. They have also bought .50 caliber rifles capable of stopping a car and Belgian pistols able to fire rifle rounds that will penetrate body armor.
Federal agents say about 90 percent of the 12,000 pistols and rifles the Mexican authorities recovered from drug dealers last year and asked to be traced came from dealers in the United States, most of them in Texas and Arizona.
Unlike a recentTimes editorial , McKinley put qualifiers on the "90 percent" figure, indicating he knows that the raw number is wrong. But the figure is still highly misleading. A Fox  News investigation  found that most guns aren't sent anywhere for tracing because it's obvious they don't come from the United States. The investigation indicated that only a fraction of guns found at crime scenes in Mexico, around 17%, were actually traced back to the United States.