Many scholars have written about the police, but almost all have done so from the outside. Rosa Brooks, a law professor at Georgetown University, is one of the few exceptions. In 2016, Brooks—already a successful scholar of national security law and a former official in the Department of Defense—joined Washington, D.C.'s volunteer Police Reserve Corps as a sworn police officer. For several years, she patrolled in some of D.C.'s most disadvantaged neighborhoods, an experience she has chronicled in her new book, "Tangled Up in Blue: Policing the American City." Alan Rozenshtein spoke with Brooks about her time in law enforcement, the structural challenges facing police in the United States and the prospects for reform.