On March 22, 2000, the frozen body of twenty-year-old Jose Luis Uriostegua was discovered on Mount Laguna in east San Diego County, nearly twenty miles north of the U.S. Mexico border. Uriostegua had fled from Guerrero, a poverty-stricken state in Mexico, in hopes of finding a better life for himself and his family in the United States. When his remains were found, Uriostegua was identified as “Number 500”—the five hundredth person to die while trying to elude the U.S. Border Patrol under California’s “Operation Gatekeeper” program.

Operation Gatekeeper began in 1994 as a U.S. Immigration and Naturalization (INS) strategy to prevent illegal immigrants from crossing the Mexico-California border. The strategy places an increased number of Border Patrol agents, extensive fencing, new roads, stadium-type lights, motion detectors, infrared night scopes, and computerized identification...