This book looks at the interplay between criminal and other branches of public law pursuing similar objectives (referred to as ''quasi-criminal law''). The need for clarifying the concepts and the interlink between criminal and quasi-criminal enforcement is a topic attracting a lot of discussion and debate both in academia and practice across Europe (and beyond). This volume adds to this debate by bringing to light the substantive and procedural problems stemming from the current parallel or dual use of the different enforcement systems. The collection draws on expertise from academia, practice and policy; its high-quality analysis will appeal to scholars, practitioners and policymakers alike.