This research explores Operation Joint Effort (OJE) as a case study of local and federal collaborations on immigration enforcement. OJE is a collective partnership between Escondido, California’s local police department and Immigration and Customs Enforcement (ICE). As individual states continue to opt into such collaborative efforts, the imperative need for a critical review is bellowing. The central concern of this thesis is of how such collaborations impact the daily routine for undocumented migrants within these boundaries of policing and reviews such boundaries by the cultural characteristics and definitions of “illegality.” This thesis is guided by ethnographic fieldwork and 16 semi-structured qualitative interviews conducted by the ACLU and myself. Tactics of immigration enforcement not only shape how “illegality” is defined, but also how those saddled with the title of “illegal” must live within the constrained environment that “illegality” creates for human begins. This thesis hopes to be clear in its understanding of “illegality” by acknowledging its various layers; first, how it is defined through various federal, state and local legislation; second, how it is sustained through enforcement tactics such as the militarization of the southern border, and deportation, which invokes fear and criminality in the general public; and third, how it is lived and experienced through the bodies of those subjected to this every-changing notion of “illegality.” I argue that through immigration enforcement tactics, like Operation Joint Effort, the Escondido Police Department instills “deportation terror” while reinforcing and restructuring the boundaries of Mexican/Latino “illegality” within Escondido’s city limits.