The criminal justice system acts directly on bodies, but fundamentally it cares about minds. As neuroscience progresses, it will increasingly be able to probe the objective, physical organ of the brain and reveal secrets from the subjective mind. This is already beginning to affect the criminal justice system, a trend that will only increase. This review article cannot begin even to sketch the full scope of the new field of law and neuroscience. The first workshop on the subject was held in 2003 (Garland 2004), but the field already has its own casebook (Jones et al. 2014) and the MacArthur Foundation Research Network on Law and Neuroscience (2018) shows more than 1,700 publications in the area between 1984 and 2017. Greely (2009) divided the implications of law into five different categories: prediction, mind-reading, responsibility, treatment, and enhancement. This article examines only three points: the current use of neuroscience to understand and explain criminal behavior, the possibilities of relevant neuroscience-based prediction, and plausible future applications of neuroscience to the treatment of criminals. But first, we discuss the human brain and how it works.