As police departments across the United States equip officers with body worn cameras (BWCs), research has focused on the technology’s impact on police interactions with citizens, officer misconduct, officer use of force, and false allegations against police. Given the large number of police agencies implementing BWCs across the country (numbering in the thousands), there will be a growing number of opportunities for BWC evaluations and expectations that these programs will be evaluated. Studying the implementation of BWCs presents a number of challenges to both researchers and police agencies, particularly when large police organizations are involved. Drawing on our experiences involving a BWC experiment with the Las Vegas Metropolitan Police Department, this article discusses the programmatic challenges of implementing a BWC program in a large agency (technical, political, and administrative) while simultaneously evaluating the program using a randomized controlled trial design.