Through our study of the Institutional Hearing Program (IHP), we examine how immigration courts within prisons enforce immigration law over individuals serving criminal sentences. Drawing from interviews with legal services providers, community advocates, and impacted immigrants in New York City, we examine due process, inequality, and legal strategies in the context of the IHP. Findings demonstrate the disproportionate punishment of Black and Brown incarcerated immigrants, as well as restricted access to information, distant placement of IHP prisons, and scarce funding for representing incarcerated individuals in immigration proceedings, all of which create challenges for legal advocates' chances of success. We argue that sanctuary provisions in NYC exclude certain migrants by marking them with the stigma of criminal records in over-surveilled neighborhoods and physically exporting them outside city borders to state prisons, where specific policies toward their expedited deportation (such as the IHP) take place. The IHP is a key site on a pipeline from incarceration to deportation that must be drastically limited, or ultimately eradicated, to ensure justice for criminalized immigrants.