¹ Bouchard, Genevieve and Carroll, Barbara Wake, “Policy-Making and Administrative Discretion: The Case of Immigration in Canada,” Canadian Public Administration 45 (2002), 239CrossRefGoogle Scholar; Gelsthorpe, Loraine and Padfield, Nicola, “Introduction,” in Exercising Discretion: Decision-Making in the Criminal Justice System and Beyond, ed. Gelsthorpe, Loraine and Padfield, Nicola (Cullompton, UK: Willan, 2003), 1Google Scholar; Gilboy, Janet A., “Deciding Who Gets In: Decisionmaking by Immigration Inspectors,” Law and Society Review 25 (1991), 571CrossRefGoogle Scholar; Gilboy, Janet A., “Penetrability of Administrative Systems: Political ‘Casework’ and Immigration Inspections,” Law and Society Review 26 (1992), 273CrossRefGoogle Scholar; Hawkins, Keith, “The Use of Legal Discretion: Perspectives from Law and Social Science,” in The Uses of Discretion, ed. Hawkins, Keith (Oxford: Clarendon, 1992), 1Google Scholar; Hawkins, Keith, Law as Last Resort: Prosecution Decision-Making in a Regulatory Agency (Oxford: Oxford University Press, 2002)Google Scholar; Pottie, Laura and Sossin, Lorne, “Demystifying the Boundaries of Public Law: Policy, Discretion and Social Welfare,” UBC Law Review 38 (2005), 147Google Scholar; Pratt, Anna, “Dunking the Doughnut: Discretionary Power, Law and the Administration of the Canadian Immigration Act,” Social and Legal Studies 8 (1999), 199CrossRefGoogle Scholar; Pratt, Anna, Securing Borders: Detention and Deportation in Canada (Vancouver: UBC Press, 2005)Google Scholar; Sossin, Lorne, “Discretion Unbound: Reconciling the Charter and Soft Law,” Canadian Public Administration 45 (2003), 465CrossRefGoogle Scholar.

² Pratt, , “Dunking the Doughnut,” 220Google Scholar.

³ Hawkins, Law as Last Resort.

⁴ To be precise, an exception is those situations where front-line officials must act on all applicants for a legal benefit, which may also entail decisions about punitive actions. Relevant examples are Bouchard and Carroll's study of applicants for Canadian immigration (“Policy-Making and Administrative Discretion”) and Weber's study of applicants for asylum in the United Kingdom: Weber, Leanne, “Decisions to Detain Asylum Seekers—Routine, Duty or Individual Choice?” in Exercising Discretion: Decision-Making in the Criminal Justice System and Beyond, ed. Gelsthorpe, Loraine and Padfield, Nicola (Cullompton, UK: Willan, 2003), 164Google Scholar.

⁵ Hawkins, , Law as Last Resort, ix, 17, 19, 425Google Scholar.

⁶ See the voluminous citations in Gelsthorpe and Padfield, “Introduction,” 7; this is a central theme in Skolnick, Jerome H., Justice without Trial: Law Enforcement in Democratic Society (New York: John Wiley, 1966)Google Scholar.

⁷ The fundamental work on front-line bureaucrats is Lipsky, Michael, Street-Level Bureaucracy: Dilemmas of the Individual in Public Services (New York: Russell Sage, 1980)Google Scholar. Bouchard and Carroll, “Policy-Making and Administrative Discretion,” and Sossin, “Discretion Unbound,” emphasize the importance of understanding the practices, training, guidelines, and so forth of street-level bureaucrats for the study of discretion in law.

⁸ The key work is Lukes, Steven, Power: A Radical View (London: Macmillan, 1974)CrossRefGoogle Scholar, and previous studies of non-decision-making cited therein.

⁹ Much the same point is made in Gilboy, , “Penetrability of Administrative Systems,” 300Google Scholar.

¹⁰ Adey, Peter, “Secured and Sorted Mobilities: Examples from the Airport,” Surveillance and Society 1 (2004), 500Google Scholar; Gandy, Oscar H., The Panoptic Sort: A Political Economy of Personal Information (Boulder, CO: Westview Press, 1993)Google Scholar; Lyon, David, “Airport Screening, Surveillance and Social Sorting: Canadian Responses to 9/11 in Context,” Canadian Journal of Criminology and Criminal Justice 48 (2006), 397CrossRefGoogle Scholar. This analysis of policing as assessing the social-constructing signs of risk benefits from Ericson, Richard V. and Haggerty, Kevin D., Policing the Risk Society (Toronto: University of Toronto Press, 1997)Google Scholar, although my analysis does not address the wider web of risk communication that they explore (but see the brief discussion of electronically accessible watchlists at ports of entry and checkpoints).

¹¹ Pratt, Securing Borders. Trust (contrasted with risk) also lurks behind the scenes in Hawkins' magisterial work, without ever being explicitly interrogated—for example, in health and safety officers' decisions to use informal negotiation and education with businesses that they trust to comply. See Hawkins, Law as Last Resort.

¹² The social scientific literature refers either to interpersonal trust (e.g., Vélez-Ibàñez, Carlos G., Bonds of Mutual Trust: The Cultural System of Rotating Credit Associations among Urban Mexicans and Chicanos (New Brunswick, NJ: Rutgers University Press, 1983)Google Scholar) or to trust in overarching social institutions (e.g., Anthony Giddens, The Consequences of Modernity (Stanford, CA: Stanford University Press, 1990)Google Scholar). My use of trust points instead to inequalities in trust accorded to specific social “types,” a middle ground between the other two usages.

¹³ Kimmel, Michael S. and Ferber, Abby L., eds., Privilege: A Reader (Boulder, CO: Westview Press, 2003)Google Scholar.

¹⁴ Adey, , “Secured and Sorted Mobilities”; Louise Amoore, “Biometric Borders: Governing Mobilities in the War on Terror,” Political Geography 25 (2006), 336Google Scholar; Sparke, Matthew, “A Neoliberal Nexus: Economy, Security and the Biopolitics of Citizenship on the Border,” Political Geography 25 (2006), 151CrossRefGoogle Scholar; Salter, Mark B., “Passports, Mobility, and Security: How Smart Can the Border Be?” International Studies Perspectives 5 (2004), 71CrossRefGoogle Scholar; Wilson, Dean, “Biometrics, Borders and the Ideal Suspect,” in Borders, Mobility and Technologies of Control, ed. Pickering, Sharon and Weber, Leanne (Dordrecht: Springer, 2006), 87CrossRefGoogle Scholar; Wilson, Dean, “Australian Biometrics and Global Surveillance,” International Criminal Justice Review 17 (2007), 207CrossRefGoogle Scholar; Wilson, Dean and Weber, Leanne, “Surveillance, Risk and Preemption on the Australian Border,” Surveillance and Society 5 (2008), 121Google Scholar.

¹⁵ The literature's concentration on increasingly explicit and powerful formal programs inadvertently gives the misleading impression that differential sorting and treatment in mobility is new or is more markedly unequal than in the recent past. Consideration of informal sorting practices shows that such features are deeply rooted and that they have significant effects even without networked and computer-processed databases and without formal trusted-traveller programs. Furthermore, formalized programs do not simply eliminate discretion but, rather, combine in new ways (as discussed in the text) important continuing elements of officer- and management-level discretion with more explicit forms of differential treatment.

¹⁶ Pratt, Securing Borders.

¹⁷ It is well known in criminology that the level and focus of policing, including discretion exercised by street-level officers, have profound effects on apparent crime rates. See Manning, Peter K., Police Work: The Social Organization of Policing (Cambridge, MA: MIT Press, 1977), 131–32, 279–93Google Scholar.

¹⁸ Hawkins, , Law as Last Resort, 42–59Google Scholar.

¹⁹ About 90% of all migration arrests are made by the Border Patrol, and over 98% of those are made at the south-west border, almost entirely of EWIs, while demographers estimate that about 45% of all unauthorized migrants come to the United States through legal modes of entry and only later violate the terms of their visas. See Modes of Entry for the Unauthorized Migrant Population (Pew Hispanic Center fact sheet, May 22, 2006), http:// pewhispanic.org/files/factsheets/19.pdf; Aaron Terrazas, Immigration Enforcement in the United States http://www.migrationinformation.org/USFocus/display.cfm?ID=697#11 (Migration Information Source, October 2008).

²⁰ Núñez, Guillermina Gina and Heyman, Josiah McC., “Entrapment Processes and Immigrant Communities in a Time of Heightened Border Vigilance,” Human Organization 66 (2007), 354CrossRefGoogle Scholar.

²¹ See United States v. Martinez-Fuerte, 428 U.S. 543 (1976); United States v. Massie, 65 F.3d 843 (10th Cir. 1995); United States v. Rascon-Ortiz, 994 F.2d 749 (10th Cir. 1993), and the discussion in Hing, Bill Ong, Defining America through Immigration Policy (Philadelphia: Temple University Press, 2003), 140–42Google Scholar.

²² United States v. Brignoni-Ponce, 422 U.S. 873 (1975); also see United States v. Almeida-Sanchez, 413 U.S. 266 (1973).

²³ Lee Maril, Robert, Patrolling Chaos: The U.S. Border Patrol in Deep South Texas (Lubbock: Texas Tech University Press, 2004)Google Scholar.

²⁴ On this phenomenon see Skolnick, Justice without Trial.

²⁵ On unauthorized residency see Modes of Entry; also see Quintanilla, Michael and Copeland, Peter, ‘“Mexican Maids’: El Paso's Worst Kept Secret,” in U.S.-Mexico Borderlands: Historical and Contemporary Perspectives, ed. Martínez, Oscar J. (Wilmington, DE: Scholarly Resources, 1996), 213Google Scholar.

²⁶ See SENTRI Program Description: Secure Electronic Network for Travelers Rapid Inspection (US Customs and Border Protection, 2009), http://www.customs.gov/xp/cgov/travel/trusted_traveler/sentri/sentri.xml.

²⁷ I make this generalization about the composition of SENTRI participants with confidence, based on my “local knowledge,” but it has no rigorous empirical verification.

²⁸ Most people who cross the border are entered into deportation proceedings, an administrative (not criminal) process; they may be offered and accept voluntary departure, which bypasses formal deportation (and thus truncates any further review); some are formally deported, a choice that involves complex discretionary decision-making at several immigration policing and judiciary levels. Illegal entry is the criminal form of entry without inspection (8 U.S.C. § 1325) that can be proposed by Border Patrol officers, with the approval of managers, for prosecution by federal attorneys. Until recently, it was a rare charge, sometimes used to discipline perceived bad actors, smugglers, and so on. Recently, it has been applied by policy uniformly to all arrestees in certain low-volume sectors of the border region and at the discretion of Border Patrol managers and federal prosecutors in some higher-volume sectors. The misdemeanour charge is used for first-time offenders, but repeat unauthorized crossers are sometimes charged with felony illegal entry. See the data compiled by Transactional Records Access Clearinghouse (TRAC), Immigration Enforcement: The Rhetoric, the Reality (Trac Reports Inc., 2007), http://trac.syr.edu/immigration/reports/178/; and TRAC, Surge in Immigration Prosecutions Continues (TRAC Reports Inc., 2008)Google Scholar, http://trac.syr.edu/immigration/reports/188/.

²⁹ On everyday Border Patrol tactics near the boundary see Maril, Patrolling Chaos.

³⁰ Maril, Patrolling Chaos.

³¹ Dunn, Timothy J., Blockading the Border and Human Rights: The El Paso Operation That Remade Immigration Enforcement (Austin: University of Texas Press, 2009)Google Scholar.

³² Ibid.

³³ See Quintanilla and Copeland, “Mexican Maids,” and Gilboy, , “Penetrability of Administrative Systems,” 302Google Scholar.

³⁴ Local law-enforcement entities (city police departments, county sheriffs, state police) represent a significant presence in these zones of everyday life in the borderlands. These entities vary in terms of whether or not they try, during minor contacts such as traffic stops, to insist on identification of nationality and immigration status and to hold possible unauthorized immigrants for turnover to federal authorities. Local jails also vary in their policies of identification and turnover for various levels of crime. And federal officers have discretion as to whether or not to accept inquiries/turnovers from non-federal law-enforcement personnel. See Coleman, Mathew, “Immigration Geopolitics Beyond the Mexico–US Border,” Antipode 38 (2007), 54CrossRefGoogle Scholar, who discusses these issues for the interior of the country.

³⁵ Minor border laws (e.g., unauthorized pharmaceutical importation) are enforced sporadically, either by specialized investigations, because of obvious nervousness on the part of a border crosser, or by an attentive officer who cares to make the extra, largely unrewarded effort.

³⁶ On officer frameworks see Heyman, Josiah McC., “Putting Power into the Anthropology of Bureaucracy: The Immigration and Naturalization Service at the Mexico–United States Border,” Current Anthropology 36 (1995), 261Google Scholar; Heyman, Josiah McC., “Respect for Outsiders? Respect for the Law? The Moral Evaluation of High-Scale Issues by US Immigration Officers,” Journal of the Royal Anthropological Institute (n.s.) 6 (2000), 635CrossRefGoogle Scholar; Heyman, Josiah McC., “Class and Classification on the U.S.–Mexico Border,” Human Organization 60 (2001), 128CrossRefGoogle Scholar. On ideologies in the wider society see Inda, Jonathan X., Targeting Immigrants: Government, Technology, and Ethics (Oxford: Blackwell, 2005)Google Scholar; Nevins, Joseph, Operation Gatekeeper: The Rise of the “Illegal Alien” and the Making of the U.S.–Mexico Boundary (New York: Routledge, 2002)Google Scholar; Ngai, Mae M., Impossible Subjects: Illegal Aliens and the Making of Modern America (Princeton, NJ: Princeton University Press, 2004)Google Scholar. On the concept of “symbolic assailant” in policing see Skolnick, Justice without Trial.

³⁷ Leiken, Robert S. and Brooke, Steven, “The Quantitative Analysis of Terrorism and Immigration: An Initial Exploration,” Terrorism and Political Violence 18 (2006), 503CrossRefGoogle Scholar.

³⁸ See Maril, Patrolling Chaos.

³⁹ This discussion is based on my ethnographic research (see note 36 above), supplemented by Gilboy's work, which was done mostly at an airport not located on a border (see note 1 above).

⁴⁰ US Government Accountability Office, Border Security: Despite Progress, Weaknesses in Traveler Inspections Exist at Our Nation's Ports of Entry (Report 08-219, 2007); also see Ward, Nicholas Dudley et al. , “Observed and Perceived Inconsistencies in U.S. Border Inspections,” Journal of Homeland Security and Emergency Management 5, 1 (2008)Google Scholar, art. 17, http://www.bepress.com/jhsem/vol5/iss1/17.

⁴¹ A (then) Border Patrol officer described his sorting task at a highway checkpoint as follows: “We stopped cars from the south [Mexico] or U.S. border states with Hispanic people in the car. We were not trying to discriminate, but the numbers of Hispanics you catch are tremendous; really, it's almost only Hispanics.” He subsequently sought to separate his personal identity from the discriminatory implications of this organizational imperative. This highly interesting interview is reproduced in Heyman, Josiah McC., “U.S. Immigration Officers of Mexican Ancestry as Mexican Americans, Citizens, and Immigration Police,” Current Anthropology 43 (2002), 489CrossRefGoogle Scholar.

⁴² For simplicity of presentation, I have listed individual characteristics, but another layer of decision making has to do with combinations of individuals and the officer's socially. based stories about what such a group might be doing together (e.g., a darker-skinned and/or poorer family group may be targeted as a possible case of transporting unauthorized children, whereas an apparently richer or whiter family group is highly unlikely to be stopped, thanks to a mental interpretation about their more likely social legitimacy as travellers within the United States).

⁴³ E.g., Gilboy “Deciding Who Gets In.”

⁴⁴ Non-US, non-Mexican nationals are sorted in complex ways; for example, officials might not be highly suspicious of Europeans or Canadians (who are presumed to be tourists) while being very suspicious of Middle Easterners and South Asians (as potential terrorists).

⁴⁵ This concept is discussed in Heyman, “Class and Classification”; similar observations are offered by Gilboy, “Deciding Who Gets In.”

⁴⁶ On “belonging” and “belongers” see Maurer, Bill, Recharting the Caribbean: Land, Law and Citizenship in the British Virgin Islands (Ann Arbor: University of Michigan Press, 1997)CrossRefGoogle Scholar; also see “circles of membership”: Aleinikoff, T. Alexander, “The Tightening Circle of Membership,” Hastings Constitutional Law Quarterly 22 (1995), 915Google Scholar.

⁴⁷ E.g., nationality in Nevins, Operation Gatekeeper; class relations/surplus value transfer in Heyman, “Class and Classification”; legality in Inda, Targeting Immigrants; and race in Hing, Defining America.

⁴⁸ Heyman, Josiah McC., “Constructing a Virtual Wall: Race and Citizenship in U.S.–Mexico Border Policing,” Journal of the Southwest 50 (2008), 305CrossRefGoogle Scholar.

⁴⁹ Ackleson, Jason, “Border Security in Risk Society,” Journal of Borderlands Studies 20 (2005), 1CrossRefGoogle Scholar; Andreas, Peter, Border Games: Policing the U.S.–Mexico Divide (Ithaca, NY: Cornell University Press, 2000)Google Scholar; Andreas, Peter, “A Tale of Two Borders: The U.S.–Canada and U.S.–Mexico Lines After 9–11,” in The Rebordering of North America: Integration and Exclusion in a New Security Context, ed. Andreas, Peter and Biersteker, Thomas J. (New York: Routledge, 2003), 1Google Scholar; Heyman, Josiah McC., “Why Interdiction? Immigration Law Enforcement at the United States–Mexico Border,” Regional Studies 33 (1999), 619CrossRefGoogle Scholar; Nevins, Operation Gatekeeper.

⁵⁰ Gilboy, “Penetrability of Administrative Systems.”

⁵¹ On the topic of inequality in mobility, including its governance, see Cunningham, Hilary and Heyman, Josiah McC., “Introduction: Mobilities and Enclosures at Borders,” Identities 11 (2004), 289CrossRefGoogle Scholar; Pallitto, Robert and Heyman, Josiah McC., “Theorizing Cross-Border Mobility: Surveillance, Security and Identity,” Surveillance and Society 5 (2008), 315Google Scholar, http://www.surveillance-and-society.org/articles5(3)/mobility.pdf (last accessed Jan. 12, 2009).