1. We borrowed from existing literature to define far-right (see Joshua D. Freilich and Steven M. Chermak, “Preventing Deadly Encounters between Law Enforcement and American Far-Rightists,” Crime Prevention Studies 25 (2009), pp. 141–172; Joshua D. Freilich et al., “Open Source Research and Terrorism Studies: Introducing the United States Extremist Crime Database (ECDB)” Terrorism and Political Violence (forthcoming). The far-right subscribes to aspects of the following ideals: They are fiercely nationalistic (as opposed to universal and international in orientation), antiglobal, suspicious of centralized federal authority, reverent of individual liberty (especially their right to own guns, be free of taxes), believe in conspiracy theories that involve a grave threat to national sovereignty and/or personal liberty and a belief that one's personal and/or national “way of life” is under attack and is either already lost or that the threat is imminent (sometimes such beliefs are amorphous and vague, but for some the threat is from a specific ethnic, racial, or religious group), and a belief in the need to be prepared for an attack either by participating in paramilitary preparations and training and survivalism. The mainstream conservative movement and the mainstream Christian right are not included.

2. Our sampling design of hate groups relied on reports from the Southern Poverty Law Center. According to the Southern Poverty Law Center, “Hate Map” (2011). Available at http://www.splcenter.org/get-informed/hate-map (accessed 1 March 2012), “all hate groups have beliefs or practices that attack or malign an entire class of people, typically for their immutable characteristics.” Critical to this study was that there was a complete listing of hate groups that participated in various types of activities, including “criminal acts, marches, rallies, speeches, meetings, leafleting or publishing.” By using this source for sampling, we are able to compare the organizational characteristics of hate groups that participated in violent criminal activities to those that participated in other hate group activities.

3. Freilich et al., “Open Source Research.”

4. Andrew Blejwas, Anthony Griggs, and Mark Potok, “‘Terror from the Right’: Almost 60 Terrorist Plots Uncovered in the U.S.,” Southern Poverty Law Center Intelligence Report 118 (2005).

5. K. Jack Riley, Gregory Trevorton, Jeremy Wilson, and Lois Davis, State and Local Intelligence in the War on Terrorism (Santa Monica, CA: RAND Corporation, 2005).

6. Joshua D. Freilich, Steven M. Chermak, and Joseph Simone Jr., “Surveying American State Police Agencies about Terrorism Threats, Terrorism Sources, and Terrorism Definitions,” Terrorism and Political Violence 21 (2009), pp. 450–475. See also Joseph R. Carlson, ‘‘The Future Terrorists in America,’’ American Journal of Police 14 (1995), pp. 71–91.

7. Pete Simi, Radicalization and Recruitment among Right-wing Terrorists. An Exploratory Approach (Washington, DC: United States Department of Justice, 2009), p. 29.

8. Mark S. Hamm, Terrorism as Crime: From Oklahoma City to Al-Qaeda and Beyond (Boston: Northeastern University Press, 2007); Cynthia Lum, Leslie W. Kennedy, and Alison J. Sherley, “The Effectiveness of Counter-Terrorism Strategies: A Campbell Systematic Review” (2009). Available at www.campbellcollaboration.org/lib/download/53/ (accessed january 2010); Aerial Merari, “Academic Research and Government Policy on Terrorism,” Terrorism and Political Violence 3 (1991), pp. 88–102; Andrew Silke, “The Devil You Know: Continuing Problems with Research on Terrorism,” Terrorism and Political Violence 13 (2001), pp. 1–14.

9. Gary LaFree and Laura Dugan, “How Does Studying Terrorism Compare to Studying Crime?” Sociology of Crime, Law and Deviance 5 (2004), pp. 53–74; Robert S. Leiken and Steven Brooke, “The Quantitative Analysis of Terrorism and Immigration: An Initial Exploration,” Terrorism and Political Violence 18 (2006), pp. 503–521; Jeffrey I. Ross, “Structural Causes of Oppositional Political Terrorism: Towards a Causal Model,” Journal of Peace Research 30 (1993), pp. 317–329; Marc Sageman, Understanding Terror Networks (Philadelphia: University of Pennsylvania Press, 2004); Silke, “The Devil You Know,” pp. 1–14.

10. For important exceptions see Victor Asal and R. Karl Rethemeyer, “The Nature of the Beast: Organizational Structures and the Lethality of Terrorist Attacks,” The Journal of Politics 70 (2008), pp. 437–449; Joshua Freilich, American Militias: State-Level Variations in Militia Activities (New York: LFB Scholarly Publishing, 2003); John Horgan and Tore Bjorgo, Leaving Terrorism Behind: Individual and Collective Disengagement (New York: Routledge, 2009); Gary LaFree and Erin Miller, “Desistence from Terrorism: What Can We Learn From Criminology?” Dynamics of Asymmetric Conflict 1 (2008), pp. 203–230; Victor Asal, Gary Ackerman, and R. Karl Rethemeyer, “Connections can be Toxic: Terrorist Organizational Factors and the Pursuit of CBRN Weapons,” Studies in Conflict and Terrorism 35 (2012), pp. 229–254.

11. Asal and Rethemeyer, “The Nature of the Beast,” p. 447. See also Randy Borum, Psychology of Terrorism (Tampa: University of South Florida, 2004); Rex A. Hudson, Who Becomes a Terrorist and Why? (Guilford: The Lyons Press, 1999); Brian Lai, “Explaining Terrorism Using the Framework of Opportunity and Willingness: An Empirical Examination of International Terrorism,” Department of Political Science, University of Iowa, Iowa City, IA, 2004.

12. Michael Barkun, “Millenarian Aspects of White Supremacist Movements,” Terrorism and Political Violence 1 (1989), pp. 409–434; Michael Barkun, “Millenarian Groups and Law Enforcement Agencies: The Lessons of Waco,” Terrorism and Political Violence 6 (1994), pp. 75–95; Randy Blazak, “White Boys to Terrorist Men: Target Recruitment of Nazi Skinheads,” American Behavioral Scientist 44 (2001), pp. 982–1000; David Brannon, “The Evolution of the Church of Israel: Dangerous Mutations,” Terrorism and Political Violence 11 (1999), pp. 106–118; Martha Crenshaw, “How Terrorism Declines,” Terrorism and Political Violence 3 (1991), pp. 69–87; Audrey K. Cronin, “How al-Qaida Ends: The Decline and Demise of Terrorist Groups,” International Security 1 (2006), pp. 7–48; Martin Durham, “The American Far Right and 9/11,” Terrorism and Political Violence 15 (2003), pp. 96–111; Joshua D. Freilich, Steven M. Chermak, and David J. Caspi, “Critical Events in the Life Trajectories of Domestic Extremist White Supremacist Groups: A Case Study,” Criminology and Public Policy 8 (2009), pp. 497–530; Jeffrey Kaplan, “Leaderless Resistance,” Terrorism and Political Violence 9 (1997), pp. 80–95; George Michael, “RAHOWA! A History of the World Church of the Creator,” Terrorism and Political Violence 18 (2006), pp. 561–583; Brent L. Smith and Kelly R. Damphousse, “Patterns of Precursor Behaviors in the Life Span of a U.S. Eco-terrorist Group,” Criminology and Public Policy 8 (2009), pp. 475–496.

13. Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449; Jeff Victoroff, “The Mind of the Terrorist: A Review and Critique of Psychological Approaches,” Journal of Conflict Resolution 49 (2005), pp. 3–42.

14. See Freilich, American Militias; Joshua D. Freilich and William A. Pridemore, “A Reassessment of State-Level Covariates of Militia Groups,” Behavioral Sciences and the Law 23 (2005), pp. 527–546; Sean O’Brien and Donald P. Haider-Markel, “Fueling the Fire: Social and Political Correlates of Citizen Militia Activity,” Social Science Quarterly 79 (1998), pp. 456–465; Nella Van Dyke and Sarah A. Soule, “Structural Change and the Mobilizing Effect of Threat: Explaining Levels of Patriot and Militia Organizing in the United States,” Social Problems 49 (2002), pp. 497–520; Rory McVeigh, “Structured Ignorance and Organized Racism in the United States,” Social Forces 82(3) (2008), pp. 895–936.

15. Gary LaFree, Laura Dugan, and Raven Korte, “The Impact of British Counterterrorist Strikes on Political Violence in Northern Ireland: Comparing Deterrence and Backlash Models,” Criminology 47 (2009), pp. 17–45; Gary LaFree, Laura Dugan, Min Xie, and Piyusha Singh, “Spatial and Temporal Patterns of Terrorist Attacks by ETA, 1970 to 2007,” Journal of Quantitative Criminology 28(1), pp. 7–29.

16. Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530; Lum, Kennedy, and Sherley, “The Effectiveness of Counter-Terrorism Strategies.”

17. Steven M. Chermak, Joshua D. Freilich, and Zachary Shemtob, “Law Enforcement Training and the Domestic Far-Right,” Criminal Justice and Behavior 36 (2009), pp. 1305–1322; Freilich and Chermak, “Preventing Deadly Encounters”, pp. 141–172; Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530; Simi, Radicalization and Recruitment.

18. Kent L. Oots, “Organizational Perspectives on the Formation and Disintegration of Terrorist Groups,” Terrorism 12 (1989), p. 139.

19. Gary LaFree and Laura Dugan, “Research on Terrorism and Countering Terrorism,” Crime and Justice 38 (2009), pp. 413–477; David C. Rapoport, “Terrorism,” in M. E. Hawksworth and Maurice Kogan, eds., Encyclopedia of Government and Politics, Vol. II (New York: Routledge, 1992), pp. 1067–1070.

20. Michael C. Horowitz, “Nonstate Actors and the Diffusion of Innovations: The Case of Suicide Terrorism,” International Organization 64 (2010), p. 38.

21. Betty A. Dobratz and Stephanie L. Shanks-Meile, White Power, White Pride! The White Separatist Movement in the United States (New York: Twayne Publishers, 1997); Freilich, American Militias; Freilich and Pridemore, “Covariates of Militia Groups,” pp. 527–546; Mark S. Hamm, American Skinheads: The Criminology and Control of Hate Crime (Westport, CT: Praeger, 1993); Mark S. Hamm, In Bad Company: Inside America's Terrorist Underground (Boston: Northeastern University Press, 2002); John Horgan, “Leaving Terrorism Behind: An Individual Perspective,” in Andrew Silke, ed., Terrorists, Victims, and Society: Psychological Perspectives on Terrorism and Its Consequences (West Sussex, England: John Wiley and Sons Ltd., 2003); John Horgan and Max Taylor, “Playing the ‘Green Card’-Financing the Provisional IRA: Part I,” Terrorism and Political Violence 11 (1999), pp. 1–38; Holly J. McCammon, Ellen M. Granberg, Karen F. Campbell, and Christine Mowery, “How Movements Win: Gendered Opportunity Structures and U.S. Women's Suffrage Movements, 1866–1919,” American Sociological Review 66 (2001), pp. 49–70; John D. McCarthy and Mayer N. Zald, “Resource Mobilization and Social Movements: A Partial Theory,” American Sociological Review 82 (1977), pp. 1212–1241; Jessica Stern, Terror in the Name of God: Why Religious Militants Kill (New York: HarperCollins Publishers, 2003); Mayer N. Zald and John D. McCarthy, Social Movements in an Organizational Society (New Brunswick, NJ: Transaction Books, 1987).

22. Hamm, Terrorism as Crime.

23. Horowitz, “The Case of Suicide Terrorism,” pp. 33–64.

24. Simi, Radicalization and Recruitment.

25. Dobratz and Shanks-Meile, White Power, White Pride; Robert Futrell and Pete Simi, “Free Spaces, Collective Identity, and the Persistence of U.S. White Power Identity,” Social Problems 51 (2004), pp. 16–42; Pete Simi and Robert Futrell, “Negotiating White Power Activist Stigma,” Social Problems 56 (2009), pp. 89–110.

26. Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530.

27. Raphael S. Ezekiel, The Racist Mind (New York: Penguin, 1995).

28. Horgan, “Leaving Terrorism Behind,” pp. 109–130.

29. See also Simi, Radicalization and Recruitment.

30. Steven M. Chermak, Searching for a Demon: The Construction of the Militia Movement (Boston: Northeastern University Press, 2002); Sageman, Understanding Terror Networks; Simi, Radicalization and Recruitment; Leonard Weinburg and William L. Eubank, “Recruitment of Italian Political Terrorists,” in Martin Slann and Bernard Schechterman, eds., Multidimensional Terrorism (Boulder: Lynne Rienner Publishers, 1987), pp. 81–94.

31. Weinburg and Eubank, “Recruitment of Italian Political Terrorists,” pp. 81–94.

32. Sageman, Understanding Terror Networks.

33. Bruce Hoffman, Inside Terrorism (New York: Columbia University Press, 2006).

34. Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530; Saad E. Ibrahim, “Anatomy of Egypt's Militant Islamic Groups: Methodological Note and Preliminary Findings,” International Journal of Middle East Studies 12 (1980), pp. 423–453; Saad E. Ibrahim, “Egypt's Islamic Militants,” MERIP Reports 103 (1982), pp. 5–14; Sageman, Understanding Terror Networks; Simi, Radicalization and Recruitment.

35. Canadian Centre for Intelligence and Security Studies, “Actual and Potential Links between Terrorism and Criminality,” Trends in Terrorism Series 5 (2006), p. 5. Available at http://www3.carleton.ca/cciss/res_docs/itac/omalley_e.pdf (accessed 1 May 2008).

36. Steven M. Chermak, Joshua Freilich, Andrew J. Bringuel, and James Shearer, “Terrorism and Counterfeiting: A Synopsis of Critical Issues and Research Opportunities,” in Andrew J. Bringuel, Jenelle C. Janowicz, Abelardo C. Valida, and Edna F. Reid, eds., Terrorism Research and Analysis Project: A Collection of Thoughts, Ideas, and Perspectives Vol. I (Washington, DC: Government Printing Office, 2011), pp. 149–187; Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530; Horowitz, “The Case of Suicide Terrorism,” pp. 33–64.

37. Doug McAdam, Political Process and the Development of Black Insurgency, 1930–1970 (Chicago: University of Chicago Press, 1982); John D. McCarthy and Mayer N. Zald, “Resource Mobilizations and Social Movements: A Partial Theory,” in Mayer N. Zald and John D. McCarthy, eds., Social Movements in Organized Society (New Brunswick, NJ: Transaction Press, 1987), pp. 15–42; Aldon D. Morris, Origins of the Civil Rights Movement (Chicago: Free Press, 1984); Van Dyke and Soule, “Structural Change and the Mobilizing Effect,” pp. 497–520.

38. James A. Aho, The Politics of Righteousness: Idaho Christian Patriotism (Seattle: University of Washington Press, 1990); Sara Diamond, Roads to Dominion: Right-Wing Movements and Political Power in the United States (New York: Guilford Press, 1995); Dobratz and Shanks-Meile, White Power, White Pride!; Freilich American Militias; Hamm, American Skinheads.

39. Stern, Terror in the Name of God, p. 142.

40. Sioban O’Neil, Terrorist Precursor Crimes: Issues and Options for Congress (Washington, DC: Congressional Research Service, 2007). See also Thomas M. Sanderson, “Transnational Terror and Organized Crime: Blurring the Lines,” SAIS Review 24 (2004), pp. 49–61; Gregory F. Treverton, Karla J. Cunningham, Jeremiah Goulka, Greg Ridgeway, and Anny Wong, Film Piracy, Organized Crime, and Terrorism (Santa Monica: RAND Corporation, 2009).

41. Horowitz, “The Case of Suicide Terrorism,” pp. 33–64.

42. See James Ranger-Moore, “Bigger may be Better, but is Older Wiser? Organizational Age and Size in the New York Life Insurance Industry,” American Sociological Review 62 (1997), pp. 903–920.

43. Horowitz, “The Case of Suicide Terrorism,” p. 45; See also S. Brock Blomberg, Rozlyn C. Engel and Reid Sawyer, “On the Duration and Sustainability of Transnational Terrorist Organizations,” Journal of Conflict Resolution 54 (2010), pp. 303–330; Asal, Ackerman, and Rethemeyer, “Connections can be Toxic.”

44. Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449.

45. Chermak, Searching for a Demon.

46. David Caspi, “Extremist Networks and Lethality: A Mapping of Violent White Supremacist Group Networks and Investigation of Relationship between Network Location and Ideologically Motivated Murder” (Ph.D. diss., John Jay College, City University of New York, 2010.

47. Asal, Ackerman, and Rethemeyer, “Connections can be Toxic,” p. 243.

48. Asal and Rethemeyer, “The Nature of the Beast,” 437–449; Horowitz, “The Case of Suicide Terrorism,” pp. 33–64. See also Seth G. Jones and Martin C. Libicki, How Terrorist Groups End: Lessons for Countering Al Qaeda (Santa Monica, CA: RAND Corporation, 2008).

49. Jones and Libicki, How Terrorist Groups End.

50. Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449.

51. Horowitz, “The Case of Suicide Terrorism,” pp. 33–64.

52. Caspi, “Extremist Networks and Lethality.”

53. Oots, “Formation and Disintegration of Terrorist Groups,” pp. 139–152.

54. See Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449; Horowitz, “The Case of Suicide Terrorism,” pp. 33–64; Asal, Ackerman, and Rethemeyer, “Connections can be Toxic.”

55. Federal Bureau of Investigation, White Supremacist Recruitment of Military Personnel since 9/11 (Washington, DC: FBI Counterterrorism Division, 2008); Department of Homeland Security, Rightwing Extremism: Current Economic and Political Climate Fueling Resurgence in Radicalization and Recruitment (Washington, DC: Department of Homeland Security, Office of Intelligence and Analysis, 2009).

56. Brent L. Smith, Kelly Damphousse, Steven Chermak, and Joshua Freilich, “Right-Wing Extremism and Military Service,” in Andrew J. Bringuel, Jenelle C. Janowicz, Abelardo C. Valida and Edna F. Reid, eds., Terrorism Research and Analysis Project: A Collection of Thoughts, Ideas, and Perspectives Vol. I (Washington D. C.: Government Printing Office, 2011), pp. 345–368.

57. Ibid.

58. Asal and Rethemeyer, “The Nature of the Beast,” p. 437; See also Laura Dugan, Julie Y. Huang, Gary LaFree, and Clark McAuley, “Sudden Desistence from Terrorism: The Armenian Secret Army for the Liberation of Armenia and the Justice Commandos of the Armenian Genocide,” Dynamics of Asymmetric Conflict: Pathways toward Terrorism and Genocide 1 (2008), pp. 231–249.

59. Kathleen M. Blee, Inside Organized Racism: Women in the Hate Movement (Berkeley: University of California Press, 2002); Dobratz and Shanks-Meile, White Power, White Pride!; Freilich, Chermak and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530; McVeigh, “Structured Ignorance and Organized Racism in the United States.”

60. Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530.

61. Chip Berlet and Matthew N. Lyons, Right-Wing Populism in America: Too Close for Comfort (New York: Guilford Press, 2000); Diamond, Roads to Dominion; Freilich, American Militias; Freilich and Pridemore, “Covariates of Militia Groups,” pp. 527–546; O’Brien and Haider-Markel, “Fueling the Fire,” pp. 456–465.

62. Anthony Oberschall, Social Movements: Ideologies, Interests and Identities (New Brunswick: Transaction Press, 1993).

63. Mark Pitcavage, “Camouflage and Conspiracy: The Militia Movement from Ruby Ridge to Y2K,” American Behavioral Scientist 44 (2001), pp. 957–981.

64. Donald P. Green and Andrew Rich, “White Supremacist Activity and Cross Burnings in North Carolina,” Journal of Quantitative Criminology 14 (1998), pp. 263–282; see also Horowitz, “The Case of Suicide Terrorism,” pp. 33–64.

65. Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449; see also Green and Rich, “White Supremacist Activity,” pp. 263–282.

66. Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449; Val Burris, Emery Smith, and Ann Strahm, “White Supremacist Networks on the Internet,” Sociological Focus 33 (2000), pp. 215–234; Walter Enders and Paan Jindapon, “Network Externalities and the Structure of Terrorist Networks,” Journal of Conflict Resolution 54 (2010), pp. 262–280; Aleta Gustavson and Darren Sherkat, “The Ideological Structuring of White Supremacy on the Internet: Analyzing Network Size, Density, and Asymmetry” (paper presented at the annual meeting of the American Sociological Association, San Francisco, CA, 2004); Bert Klandermans and Dirk Oegema, “Potentials, Networks, Motivations, and Barriers: Steps towards Participation in Social Movements,” American Sociological Review 52 (1987), pp. 519–531; U.S. Army Training and Doctrine, A Military Guide to Terrorism in the Twenty-First Century (2007) Available at www.au.af.mil/au/awc/awcgate/army/guidterr/ (accessed 15 February 2012).

67. Enders and Jindapon, “Network Externalities,” pp. 262–280; Ross, “Structural Causes of Oppositional Political Terrorism,” pp. 317–329.

68. Asal and Rethemeyer, “The Nature of the Beast,” p. 440; see also Enders and Jindapon, “Network Externalities,” pp. 262–280.

69. Futrell and Simi, “Free Spaces, Collective Identity,” p. 20.

70. Enders and Jindapon, “Network Externalities,” pp. 262–280.

71. Asal and Rethemeyer, “The Nature of the Beast,” p. 447.

72. Ibid., pp. 437–449.

73. Horowitz, “The Case of Suicide Terrorism,” pp. 33–64.

74. Ibid., p. 42.

75. Ibid., p. 61.

76. Caspi, “Extremist Networks and Lethality.”

77. Oots, “Formation and Disintegration of Terrorist Groups,” pp. 147, 148.

78. Chermak, Freilich, and Shemtob, “Law Enforcement Training,” pp. 1305–1322.

79. Dobratz and Shanks-Meile, White Power, White Pride!; Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530.

80. Chermak, Searching for a Demon.

81. Ezekiel, The Racist Mind; Hamm, American Skinheads; Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530.

82. Oots, “Formation and Disintegration of Terrorist Groups,” pp. 139–152; Louise Richardson, What Terrorists Want: Understanding the Enemy, Containing the Threat (New York: Random House, 2006); Stern, Terror in the Name of God.

83. Aho, The Politics of Righteousness; Diamond, Roads to Dominion; Dobratz and Shanks-Meile, White Power, White Pride!; Clarence Lo, “Counter Movements and Conservative Movements in the Contemporary U.S.,” Annual Review of Sociology 8 (1982), pp. 107–134.

84. Freilich, Chermak, and Caspi, “Critical Events in the Life Trajectories,” pp. 497–530.

85. Hamm, American Skinheads.

86. Kevin Flynn and Gary Gerhardt, The Silent Brotherhood: The Chilling Inside Story of America's Violent, Anti-Government Militia Movement (New York: Signet, 1995); Hamm, In Bad Company; Thomas Martinez and John Guinther, Brotherhood of Murder: How One Man's Journey through Fear Brought the Order to Justice (Lincoln, NE: Excel, 1999).

87. Steven M. Chermak, Joshua D. Freilich, and Joseph Simone Jr., “Surveying American State Police Agencies about Lone Wolves, Far-Right Criminality, and Far-right and Islamic Criminal Collaboration,” Studies in Conflict and Terrorism 33 (2010), pp. 1019–1041; Kelly R. Damphousse and Brent L. Smith, “Terrorism and Empirical Testing: Using Indictment Data to Assess Changes in Terrorist Conduct,” Sociology of Crime, Law and Deviance 5 (2004), pp. 75–90; Kaplan, “Leaderless Resistance,” pp. 80–95; Pete Simi, Joshua Freilich, and Steven Chermak, “What is Lone Wolf Terrorism?,” in Andrew J. Bringuel, Jenelle C. Janowicz, Abelardo C. Valida, and Edna F. Reid, eds., Terrorism Research and Analysis Project: A Collection of Thoughts, Ideas, and Perspectives Vol. I (Washington, DC: Government Printing Office, 2011), pp. 315–343.

88. Damphousse and Smith, “Terrorism and Empirical Testing,” pp. 75–90.

89. John Arquilla, David Ronfeldt, and Michele Zanini, “Netwarks, Netwar, and Information Age Terrorism,” in Ian O. Lesser, Bruce Hoffman, John Arquilla, David Ronfeldt, and Michele Zanini, eds., Countering the New Terrorism (Santa Monica, CA: RAND, 1999); Enders and Jindapon, “Network Externalities,” pp. 262–280; Marc Sageman, Leaderless Jihad: Terror Networks in the Twenty-First Century (Philadelphia: University of Pennsylvania Press, 2008).

90. Caspi, “Extremist Networks and Lethality.”

91. David Holthouse, “Hate Crimes in Prison,” SPLC Intelligence Report (2005). Available at http://www.alternet.org/story/27726/ (accessed 1 June 2009).

92. Mark S. Hamm, Terrorist Recruitment in American Correctional Institutions: An Exploratory Study of Non-Traditional Faith Groups (Washington, DC: National Institute of Justice, 2009).

93. Samuel Nunn, “Incidents of Terrorism in the United States, 1997–2005,” Geographical Review 97 (2007), p. 106; also Ross, “Structural Causes of Oppositional Political Terrorism,” pp. 317–329.

94. Ross, “Structural Causes of Oppositional Political Terrorism,” pp. 317–329.

95. Ronald V. Clarke and Graeme R. Newman, Outsmarting the Terrorists (New York: Praeger Press, 2006); Nunn, “Incidents of Terrorism,” pp. 89–111; Brent L. Smith, Kelly R. Damphousse, and Paxton Roberts, Pre-Incident Indicators of Terrorist Incidents: The Identification of Behavioral, Geographic, and Temporal Patterns of Preparatory Conduct (Washington, DC: United States Department of Justice, 2006).

96. Chermak, Searching for a Demon; Joshua D. Freilich and William A. Pridemore, “Mismeasuring Militias: Limitations of Advocacy Group Data and of State-Level Studies of Paramilitary Groups,” Justice Quarterly 23 (2006), pp. 147–162.

97. Southern Poverty Law Center, “Hate Map” (2011). Available at http://www.splcenter.org/get-informed/hate-map (accessed 15 January 2012).

98. Ibid.

99. See Center for International Development and Conflict Management, “Minorities at Risk: Organizational Behavior” (2008). Available at http://www.cidcm.umd.edu/mar/data/marob/me_marob_sept08_codebook.pdf (accessed 20 March 2010).

David Noble, “Assessing the Reliability of Open Source Information” (paper presented at the 7th International Conference on Information Fusion, Stockholm, Sweden, 2004). Available at www.fusion2004.foi.se/papers/IF04–1172.pdf (accessed 1 June 2008).

LaFree and Dugan, “How Does Studying Terrorism,” pp. 53–74.

See Freilich and Chermak, “Preventing Deadly Encounters,” pp. 141–172.

Blomberg, Engel, and Sawyer, “Transnational Terrorist Organizations,” pp. 303–330.

We attempted to capture linkages to other domestic extremists, including linkages to far-left or jihadi organizations but we did not discover any evidence of such linkages among the groups in this study.

Kaplan, “Leaderless Resistance,” p. 80.

These results are available from the authors.

Damphousse and Smith, “Terrorism and Empirical Testing,” pp. 75–90.

Futrell and Simi, “Free Spaces, Collective Identity,” pp. 16–42.

Asal and Rethemeyer, “The Nature of the Beast,” pp. 437–449; Horowitz, “The Case of Suicide Terrorism,” pp. 33–64; Erin Miller, “Patterns of Onset and Decline among Terrorist Organizations,” Journal of Quantitative Criminology 28 (2012), pp. 77–101.

Christopher Hewitt, Understanding Terrorism in America: From the Klan to Al Qaeda (New York: Routledge, 2003).