Smart devices are increasingly the origin of critical criminal case data. The importance of such data, especially data generated when using modern automobiles, is likely to become even more important as increasingly complex methods of machine learning lead to AI-based evidence being autonomously generated by devices. This article reviews the admissibility of such evidence from both American and German perspectives. As a result of this comparative approach, the authors conclude that American evidence law could be improved by borrowing aspects of the expert testimony approaches used in Germany’s “inquisitorial” court system.