The Disappeared report series is collaborative project between two Tucson-based organizations, La Coalición de Derechos Humanos and No More Deaths. Between Derechos Humanos’ 20 years of community work, including the 24-hour Missing Migrant Crisis Line, and No More Deaths’ 12 years of humanitarian aid in the Arizona backcountry, we have witnessed and listened to thousands of stories of border crossings throughout Southern Arizona. Our research goals are transformative: to expose and combat those US government policing tactics that cause the crisis of death and mass disappearance in the borderlands. This report focuses on a discriminatory and deadly emergency response system in the borderlands. We document how Border Patrol has inserted themselves as the sole responder for undocumented migrants in need of search and rescue, fails to respond to such emergencies, and obstructs family and humanitarian search and rescue efforts.