The United States has the largest criminal justice system in the world, resolving over 18 million criminal cases each year. Given the pervasiveness and seriousness of the criminal justice function, and the amount of data collected by that system, very little criminal justice data is nationally-accessible across the United States. There is a dearth of accessible information about who is prosecuted and convicted and what kinds of ultimate outcomes they experience. This Prototype-Open Knowledge Network project on an integrated platform to connect criminal justice data across data silos seeks to establish an integrated knowledge network as the data infrastructure for making necessary connections across data systems within the criminal justice system. This platform will help improve the collective knowledge of criminal justice functioning and outcomes. It will also help in the evaluation of the influence of any bias in the system, and in the evaluation of other extralegal factors, such as the social determinants of crime. Correlating the aggregated response of the criminal justice system to crime is essential to reveal inequities and inefficiencies in the administration of justice. The knowledge network will also help advance the science of knowledge networks. <br/><br/>Beginning initially with the states of Washington and Georgia, the first outcome will be a functioning knowledge network that provides the most complete picture of criminal justice to date for these regions. The longer term objective is to extend this approach to all regions/states. The platform uses public data sets to achieve its objectives of creating a public interest information resource that works in harmony with information from criminal justice institutions like the Bureau of Justice Statistics, the National Institute of Justice, the Department of Justice, and the local courts. These jurisdictions are already producing huge amounts of data that need to be harmonized, networked, and made more transparent and meaningful for use by interested users. The knowledge network will be constructed using a user-centered approach that considers usability of the technology as well as minimization of harm caused to individuals whose data populates the knowledge network. The project will achieve these goals by re-conceptualizing data best practices in a big data world where data transparency and data harm need to be balanced.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.