Events in recent months have focused national attention on profound fractures in trust between some police departments and the communities they are charged with protecting. Though the potential for such fractures is always present given the role of police in society, building and maintaining trust between police and the public is critical for the health of American democracy. However, in an era when information technology has the potential to greatly increase transparency of police activities in a variety of ways, building and maintaining trust is challenging. Doing so likely requires steps taken by both police organizations and the public to build understanding and relationships that can sustain trust through tragic incidents that can occur in the course of policing - whether it is a citizen's or officer's life that is lost. This paper draws on the deep literature on legitimacy, procedural justice, and trust to frame three core questions that must be addressed to build and maintain mutual trust between police and the public: (1) What is the police department doing and why? (2) What are the results of the department's actions? and (3) What mechanisms are in place to discover and respond to problems from the officer to the department level? Answering these questions ensures that both the public and police have mutual understanding and expectations about the goals and tactics of policing, their side effects, and the procedures to address problems fairly and effectively, maintaining confidence over time.