The burdens and challenges of discovery—especially electronic discovery—are usually associated with civil, not criminal cases. This is beginning to change. Already common in white-collar crime cases, voluminous digital discovery is increasingly a feature of ordinary criminal prosecutions. This Article examines the explosive growth of digital evidence in criminal cases and the efforts to manage its challenges. It then advances three claims about criminal case discovery in the digital age. First, the volume, complexity, and cost of digital discovery will incentivize the prosecution and the defense to cooperate more closely in cases with significant amounts of electronically stored information (ESI). Second, cooperation between the parties will not be sufficient to address the serious challenges that digital discovery presents to the fair and accurate resolution of criminal cases. And third, for that reason, digital discovery in criminal cases needs to be regulated more closely. In crafting such regulation, courts and legislators can build on the civil procedure model, which has grappled with the challenges of electronic discovery for over two decades. The civil procedure experience suggests that cooperation between the parties, active judicial involvement, and more detailed rules are essential to the effective management of digital discovery. The civil litigation model has its limitations, however, and policymakers must chart new ground to address some of the unique demands of criminal cases. Recognizing the significant resource and bargaining disparities in criminal cases, judges need to limit certain negotiated waivers of discovery so as to prevent abuse. Where the interests of justice demand it, courts may also need to help defendants obtain access to digital discovery in detention or gather digital evidence from third parties. These and other measures can help ensure that the cost and complexity of digital discovery do not undermine the fairness and accuracy of criminal proceedings.