The growing centrality of “criminal aliens” to American immigration enforcement is one of the most significant historical shifts in the federal immigration system. However, little is known about how this dramatic restructuring of federal immigration priorities affects local criminal justice systems. Do noncitizens experience the same type of criminal justice as citizens? This Article seeks to answer this question by offering the first empirical study of how local criminal process is organized around immigration enforcement and citizenship status. It accomplishes this task by analyzing the criminal justice systems of the three urban counties that prosecute the highest number of noncitizens: Los Angeles County, California; Harris County, Texas; and Maricopa County, Arizona.
Comparative review of law, procedure, and practice in these three counties reveals that immigration’s interaction with criminal law has a far more powerful impact on local criminal practice than previously understood. Across all three counties, the practical effects of the federal government’s reliance on arrests and convictions in making enforcement decisions are felt at every stage of the criminal process: Immigration status is part of routine booking at local jails, “immigration detainers” impede release on criminal bail, immigration officials encourage criminal prosecutors to secure plea agreements that guarantee removal, and noncitizens are sometimes deported before their criminal cases are completed. Yet, there is surprising variation in how these three counties have structured their criminal practices in light of the consistently deep connections between criminal process and immigration enforcement. As this Article develops, the three jurisdictions have adopted distinct models of noncitizen criminal justice—what I term alienage neutral, illegal-alien punishment, and immigration enforcement. Each model reflects significant agreement across county agencies about the appropriate role of noncitizen status in criminal case adjudication and of local involvement in deportation outcomes. These findings have important implications for the institutional design of both local criminal systems and federal immigration enforcement.