This article discusses how the development of network analysis techniques has affected research on crime and the practice of crime control over the past two decades. It describes the contributions of network analysis to criminological research – the new questions that network analysis techniques allowed criminologists to address, the old questions that have been addressed more adequately, and the novel evidence these techniques yielded. The ways in which network analysis been used by the police and other practitioners in their efforts to prevent and control crime is reviewed, as well as the limitations of network data in understanding crime patterns.