The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has spent too much time going after small-time gun runners instead of focusing on larger operations that have supplied weapons to Mexico ’s drug cartels, according to a federal audit.

The U.S. Department of Justice ’s inspector general reviewed ATF’s “Operation Gunrunner” which was launched to halt the smuggling of high-powered guns to Mexico. The IG concluded that agents were concentrating their efforts on small cases because supervisors wanted quick closure to improve agency statistics. Under the ATF program, more than 68% of the 1,015 cases sent to federal prosecutors from 2004-2009 had only one defendant and another 15% had two.