WASHINGTON — U.S. law enforcement agencies have significantly built up networks of Mexican informants that have allowed them to secretly infiltrate some of that country’s most powerful and dangerous criminal organizations, according to security officials on both sides of the border.
As the United States has opened new law enforcement and intelligence outposts across Mexico in recent years, Washington’s networks of informants have grown there as well, current and former officials said. They have helped Mexican authorities capture or kill about two dozen high and midlevel drug traffickers, and sometimes have given U.S. counternarcotics agents access to the top leaders of the cartels they are trying to dismantle.
Typically, the officials said, Mexico is kept in the dark about the United States’ contacts with its most secret informants — including Mexican law enforcement officers, elected officials and cartel operatives — partly due to concerns about corruption among the Mexican police, and partly because of laws prohibiting U.S. security forces from operating on Mexican soil.
“The Mexicans sort of roll their eyes and say we know it’s happening, even though it’s not supposed to be happening,” said Eric L. Olson, an expert on the Mexican security matters at the Woodrow Wilson Center. “That’s what makes this so hard. The United States is using tools in a country where officials are still uncomfortable with those tools.”
In recent years, Mexican attitudes about U.S. involvement in matters of national security have softened, as waves of drug-related violence have left some 40,000 people dead. And the United States, hoping to shore up Mexico’s stability and prevent that country’s violence from spilling across the border, has expanded its role in ways unthinkable five years ago, including flying drones over Mexican skies.
The efforts have been credited with breaking up several of Mexico’s largest cartels into smaller — and presumably less dangerous — crime groups. However, the violence continues, as does the northward flow of illegal drugs.
While using informants remains a largely clandestine affair, several recent cases have shed light on the kinds of investigations they have helped crack, including a plot earlier this month in which the United States accused an Iranian-American car salesman of attempting to hire hit men from a Mexican drug cartel, known as Los Zetas, to assassinate the Saudi ambassador to Washington.