This Article critiques, on legal and empirical grounds, the growing trend of basing criminal sentences on actuarial recidivism risk prediction instruments that include demographic and socioeconomic variables. I argue that this practice violates the Equal Protection Clause and is bad policy: an explicit embrace of otherwise- condemned discrimination, sanitized by scientific language. To demonstrate that this practice raises serious constitutional concerns, I comprehensively review the relevant case law, much of which has been ignored by existing literature. To demonstrate that the policy is not justified by countervailing state interests, I review the empirical evidence underlying the instruments. I show that they provide wildly imprecise in...