There is agreement in the literature that offenders often acquire guns through unregulated private encounters with friends, family members and petty criminals. Although anecdotes suggest that licensed gun dealers also play a role, most studies have ignored or discounted the possibility that dishonest retailers are a significant source of supply. This effort explores gun markets in Los Angeles by examining the redistributive history of firearms seized by police and by reviewing Federal gun trafficking investigations. One finding, that corrupt licensed dealers diverted sizeable quantities of guns to end users and to unlicensed street vendors, suggests that retail sources may serve as a far more important source of firearms for criminals than is commonly supposed.