In 2014, the California Department of Corrections and Rehabilitation began a demonstration of theEnhanced Drug and Contraband Interdiction Program at 11 prisons in California. Using data provided bythe Department, this study finds that the intensive version of the program yielded a 23% decline in failurerates of random drug tests over the period studied, and a reduction in the number of cellphone violations,but that these same institutions experienced increased levels of drug-related rules violations. Themoderate program had no discernable impact on drug abuse in the prisons in which it was tested.