New technologies have changed the types of data that are routinely collected about citizens on a daily basis, and as technology evolves, new portable and connected devices have the potential to gather even more information. Such data have great potential utility in criminal justice proceedings, and they are already being used in case preparations, plea negotiations, and trials. However, the expansion of technological capability also has the potential to stress approaches for ensuring that individuals' constitutional rights are protected through legal processes. In an effort to consider those implications, the authors convened a panel of criminal justice practitioners, legal scholars, and individuals from the civil liberties community to identify research and other needs to prepare the U.S. legal system both for technologies seen today and for technologies likely seen in the future. The panel explored a wide range of potential issues regarding these technologies, from evidentiary and procedural concerns to questions about the technologies' accuracy and efficient use. Via a Delphi-based prioritization of the results, the panel crafted a research agenda — including best practice and training development, evaluation, and fundamental research efforts — to provide the criminal justice community with the knowledge and capabilities needed to address these important and complex technological questions going forward.