This paper examines how contemporary criminal law addresses the rising complexity of transna-tional and macro-criminality, focusing on the interaction between digital evidence, cross-border cooperation, and the legal characterisation of offences. As organised criminal networks and atrocity crimes increasingly unfold across multiple jurisdictions and rely on digital technologies, investigative and prosecutorial practices have undergone notable change. Yet these developments have not always translated into stronger accountability. Using crimes committed against migrants and refugees in Libya and along the Central Mediterranean route as a case study, the paper analyses how abuses are documented, investigated, and prosecuted across domestic, regional, and international fora. It first considers the growing reliance on digital and open-source evidence and assesses both its potential for establishing broader patterns of criminality and the challenges it poses for authentication, preservation, and admissibility. The paper then examines evolving cooperation mechanisms, including Joint Investigation Teams and Joint Teams, which merge approaches traditionally associated with transnational organised crime with those of international criminal law. While these tools have facilitated arrests and improved information-sharing, their effectiveness remains tied to domestic legal frameworks and jurisdictional constraints. Finally, the paper identifies a persistent gap between investigative progress and prosecutorial outcomes. National authorities continue to pursue migration-related offences more readily than trafficking or crimes against humanity, even where evidence reflects organised and systematic patterns of abuse. The paper concludes that meaningful accountability requires aligning investigative innovation with the domestic application of international crimes, supported by robust evidentiary methods and sustained cross-border cooperation.