Two men have pleaded guilty to buying guns that were destined to be smuggled into Mexico, the first convictions in the federal government’s botched Operation Fast and Furious.

The men were so-called “straw buyers” who acknowledged purchasing guns that they knew were headed to Mexico.

The goal of the federal government’s investigation was to catch weapons-trafficking kingpins, but firearms agents lost track of many weapons they were trying to trace to smuggling ringleaders, and some guns ended up at crime scenes in Mexico and the U.S.

Jacob Wayne Chambers and Jacob Anthony Montelongo each pleaded guilty Monday in federal court to a conspiracy charge.

The pair admitted to being part of a 20-person smuggling ring that’s accused of running guns into Mexico for use by the Sinaloa drug cartel.