Professor Samuel Buell (Duke University, USA) gave a lecture entitled "The Global Expansion of Corporate Criminal Liability: Effective Enforcement Policy Across Legal Systems" on 12 February 2019 at the Faculty of Law as a guest of 3CL. The United States model of corporate crime control, developed over the last two decades, couples an extremely broad rule of corporate criminal liability with a practice of reducing sanctions, and often withholding conviction, for firms that assist in public enforcement by detecting, reporting, and helping prove criminal violations. This model has recently attracted more interest among law reformers in overseas nations, who have sought to increase the frequency and size of their own enforcement actions by adopting features of the U.S. approach. By focusing almost entirely on the law of corporate criminal liability and the process of criminal settlement, the international discussion of corporate criminal enforcement law and policy, as well as the literature on corporate crime, have missed how the U.S. model depends on what we term background laws. These are rules such as self-incrimination rights, legal privileges, and data privacy regimes that control the relative powers of governments and corporations to collect and use evidence of business crime. This Article exposes that omission, explains how background laws operate and differ in the U.S. and overseas, and advises law reformers on how to shape corporate enforcement policy in light of domestic law’s allocation of investigative powers between public and private spheres. For more information see the Centre for Corporate and Commercial Law website at http://www.3cl.law.cam.ac.uk/