Domestic terrorism or homegrown terrorism is a form of terrorism in which victims "within a country are targeted by a perpetrator with the same citizenship" as the victims. There are many definitions of terrorism, and none of them are universally accepted. The United States Department of State defined terrorism in 2003 as "premeditated, politically motivated violence perpetrated against noncombatant targets by subnational groups or clandestine agents, usually intended to influence an audience."
While there are many potential definitions of domestic terrorism, it is largely defined as terrorism in which the perpetrator targets his/her own country. Enders defines domestic terrorism as "homegrown in which the venue, target, and perpetrators are all from the same country." The term “homegrown terrorism” stems from jihadi terrorism against Westerners. Wilner and Dobouloz described homegrown terrorism as "autonomously organized radicalized Westerners with little direct assistance from transnational networks, usually organized within the home or host country, and targets fellow nationals."  The Congressional Research Service report, American Jihadist Terrorism: Combatting a Complex Threat, describes homegrown terrorism as a “terrorist activity or plots perpetuated within the United States or abroad by American citizens, permanent legal residents, or visitors radicalized largely within the United States.”
Under the 2001 USA Patriot Act, domestic terrorism is defined as "activities that (A) involve acts dangerous to human life that are a violation of the criminal laws of the U.S. or of any state; (B) appear to be intended (i) to intimidate or coerce a civilian population; (ii) to influence the policy of a government by intimidation or coercion; or (iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and (C) occur primarily within the territorial jurisdiction of the U.S." This definition is made for the purposes of authorizing law enforcement investigations. While international terrorism ("acts of terrorism transcending national boundaries") is a defined crime in federal law, no federal criminal offense exists which is referred to as "domestic terrorism". Acts of domestic terrorism are charged under specific laws, such as killing federal agents or "attempting to use explosives to destroy a building in interstate commerce".
Facts and studies
Homegrown terrorism is not new to the world. Security analysts have argued that after the end of the Cold War, military conflicts have increasingly involved violent non-state actors carrying out asymmetric warfare, of which terror attacks are one part. The United States has uncovered a number of alleged terrorist plots that have been successfully suppressed through domestic intelligence and law enforcement. The United States has begun to account for the threat of homegrown terrorism, as shown by increased volume of literature on the subject in recent years and increased number of terrorist websites since Abu Musab al-Zarqawi, the leader of al-Qaeda in Iraq, began posting beheading videos in 2003. A July 2009 document by the FBI estimated that there were roughly 15,000 websites and web forums that support terrorist activities, with around 10,000 of them actively maintained. 80% of these sites are on U.S.-based servers.
According to the Congressional Research Service’s study, American Jihadist Terrorism: Combatting a Complex Threat, between May 2009 and November 2010, law enforcement made arrests related to 22 homegrown jihadist-inspired terror plots by American citizens or legal residents of the U.S. This is a significant increase over the 21 plots caught in the seven interim years after the September 11 attacks. During these seven years, two plots resulted in attacks, compared to the two attacks between May 2009 and November 2010, which resulted in 14 deaths. This spike post-May 2009 shows that some Americans are susceptible to ideologies that support a violent form of jihad.
Roughly one-quarter of these plots have been linked to major international terrorist groups but an increasing number of Americans are holding high-level operational roles in these terrorist groups, especially al-Qaeda and its affiliated groups. The former CIA Director Michael Hayden called homegrown terrorism the more serious threat faced by American citizens today. The UK, likewise, considers homegrown terrorism to be a considerable threat. On June 6, 2011, Prime Minister David Cameron announced a wide-ranging strategy to prevent British citizens from being radicalized into becoming terrorists while at university. The strategy is intended to prevent extremist speakers or groups from coming to universities.
On July 23, 2019, Christopher A. Wray, the head of the FBI, said at a Senate Judiciary Committee hearing that the agency had made around 100 domestic terrorism arrests since October 1, 2018, and that the majority of them were connected in some way with white supremacy. Wray said that the Bureau was "aggressively pursuing [domestic terrorism] using both counterterrorism resources and criminal investigative resources and partnering closely with our state and local partners," but said that it was focused on the violence itself and not on its ideological basis. A similar number of arrests had been made for instances of international terrorism. In the past, Wray has said that white supremacy was a significant and "pervasive" threat to the U.S.
Lone wolf terrorism
Domestic terrorism is often linked to lone wolf terrorism. Sociologist Ramón Spaaij defines lone wolf terrorism as an act of terrorism committed by one person who "acts on his or her own without orders from—or even connections to an organization". From the late 20th to the early 21st centuries, lone wolf terrorism in the United States has primarily been associated with white supremacy, Islamic fundamentalism, anti-social, and anti-government extremists such as Charles Whitman, Timothy McVeigh, Dylann Roof, Robert Bowers, Wade Michael Page, Ted Kaczynski, Eric Rudolph, Eric Harris, Dylan Klebold, James Holmes, Omar Mateen, Stephen Paddock, and Tamerlan and Dzhokhar Tsarnaev. Many lone wolves share a common trait in that they seek acceptance from other groups but are typically met with rejection.
In their 2007 book Hunting the American Terrorist former FBI Deputy Assistant Director Terry Turchie and former FBI special agent Kathleen Puckett described six criteria to define a lone wolf:
- The act of terrorism was organized by few or only one person that was not operating with an organized group
- The individual is willing to use lethal violence to achieve their goal
- Their primary goal is ideological, political, or religious in scope
- The individual is willing to accept full-scale collateral damage
- The individual is not intending to commit suicide, unless the situation calls for it
- The individual is intending to commit homicide in order to get their message public, or to use such acts as the message
There is no one path toward violence. Homegrown terrorists have been high school dropouts, college graduates, members of the military, and cover the range of financial situations. Recent research by Matt Qvortrup in the British Journal of Politics and International Relations has suggested that domestic terrorism is a result of lack of opportunities for meaningful political engagement. Some domestic terrorists studied overseas and were exposed to radical Islamist thought, while others took their inspiration from the internet.
Marc Sageman writes in his book, Leaderless Jihad: Terror Networks in the Twenty-First Century that, contrary to popular belief, radicalization into terrorism is not the product of poverty, various forms of brainwashing, youth, ignorance, lack of education, lack of employment, lack of social responsibility, criminality, or mental illness. He says that intermediaries and English-speaking imams, such as the late Yemeni-American cleric Anwar al-Awlaki (d. 2011), who are often found through the internet on forums, provide key roles in the radicalization process. Social networks provided in forums support and build upon an individual’s radical beliefs. Prison systems are also a concern as a place of radicalization and jihadist recruiting; nearly three dozen ex-convicts who attended training camps in Yemen were believed to have been radicalized in prison. The only constant appears to be "a newfound hatred for their native or adopted country, a degree of dangerous malleability, and a religious fervor justifying or legitimizing violence that impels these very impressionable and perhaps easily influenced individuals toward potentially lethal acts of violence," according to Peter Bergen and Bruce Hoffman's September 2010 paper for the Bipartisan Policy Center.
Training for potential homegrown terrorists is often very fast paced, or rushed, as some groups under attack by U.S. forces may feel the need to implement operations “more precipitously than they might otherwise occur,” according to Bruce Hoffman. This was the case with the failed Times Square plot carried out by Faisal Shazad. Pakistani Taliban (TPP) was on record as providing financing and four months of training for Shazad directly prior to his actions in Times Square. Shazad reportedly received only three to five days of training in bomb-making.
Some individuals go abroad to a region containing extremism, predominantly Pakistan, but also Iraq, Afghanistan,Yemen or Somalia. In the case of the London Underground bombers, Mohammad Sidique Khan, the operational leader of the cell, received military and explosives training at a camp in Malakand, Pakistan in July 2003. Later he took Shezad Tanweer to Karachi, Pakistan, in late 2004 to February 2005 where they crossed the border to receive training at al-Qaeda camps in Afghanistan.
Training and usage of recruits is varied. Some, such as Shahzad, received little training and ultimately failed in their goals. Others, like the sleeper agent David Headley’s reconnaissance efforts, were essential towards Lashkar-e-Toiba’s (LeT) success in the November 2008 Mumbai attacks.
Scholars say that some lone wolves may achieve objectives, but the vast majority of individual operators fail to execute their plans because of lack of training and planning. There is also a question as to whether such individuals are radical, or suffering other problems. The American convert, Abdulhakim Muhammad (née Carlos Bledsoe), who killed a U.S. military recruiter in Little Rock, Arkansas, and wounded another, had many other targets and plans, which went awry. It was not until some time after his arrest that he first claimed to have been working for Al-Qaeda in the Arabian Peninsula (AQAP). But, investigators found no evidence of this. The lead county prosecutor said that, aside from Muhammad's self-serving statements, it was "just an awful killing", like others he had seen. Bledsoe's father described his son as "unable to process reality." He was charged with capital murder and related charges, not terrorism, and pleaded guilty.
The American Nidal Hasan, the US Army major and psychiatrist charged in the 2009 Fort Hood shooting, had come to the attention of colleagues and superiors years before the shootings; they documented their concerns about his mental state. The Department of Defense has classified the event as "workplace violence" rather than terrorism, pending Hasan's court martial. Some observers believe that his personal characteristics are more like those of other mass murderers than terrorists; he did not belong to any group.
The Somalian Al-Shabab (“the youth”) have recruited strongly in Minneapolis and St. Paul, Minnesota. The 30+ Somali-Americans received training by senior al-Qaeda leaders in Somalia. Hoffman believes this indicates that radicalization and recruitment is not an isolated, lone-wolf phenomenon unique to Somali-Americans, but that there is terrorist recruitment infrastructure in the United States. After more than a dozen of 20 American recruits were killed in fighting in Somalia, the number of Americans going to join Al-Shabab has declined since 2007-2008.
Role of the internet
“The Internet is a driver and enabler for the process of radicalization”, says a report of the Police Department of the City of New York of 2007. The internet has a wide appeal as it provides an anonymous way for like-minded, conflicted individuals to meet, form virtual relations, and discuss the radical and extremist ideology they encounter. The virtual network created in message boards or private forums further radicalizes and cements the jihadi-Salafi/racial supremacist message individuals have encountered as they build a community. The internet acts as an enabler, providing the aspiring jihadist/supremacist with a forum in which they may plan, share information on targets, weapons, and recruit others into their plans. Much of the resources needed to make weapons can be found on-line.
Inspire is an online English-language propaganda magazine published by al-Qaeda in the Arabian Peninsula (AQAP). Purported to be created by Samir Khan, a U.S. citizen and cyber-jihadist, the magazine uses American idioms and phrasing and does not appear to have British or South Asian influences in its language.
The magazine contains messages calling for western jihadists, like this one from AQAP leader Nasir al-Wahayshi, "to acquire weapons and learn methods of war. They are living in a place where they can cause great harm to the enemy and where they can support the Messenger of Allah... The means of harming them are many so seek assistance from Allah and do not be weak and you will find a way.”
STRATFOR suggests that the magazine is meant to "fan the flames of Jihad."
History and examples
- January 5–6, 2012 Nigeria attacks, around 37 Christians are targeted and killed by Boko Haram militants.
- April 16 - 2013 Baga massacre, 187 people are killed in Baga in Borno State. It is unclear whether the Nigerian military or Boko Haram is responsible for the massacre.
- June 18, 2009: Al-Shabaab claimed the 2009 Beledweyne bombing, which killed 35 people including Somali security minister Omar Hashi Aden.
- Operation Pendennis: Melbourne, Victoria & Sydney, New South Wales, Australia November 2005.
- Sydney hostage crisis: December 2014
- On October 14, 1982 - The anarchist group the Squamish Five, who were Canadian version of Direct Action, bombs a Litton Industries factory north of Toronto, Ontario, Canada that is manufacturing guidance devices for American cruise missiles, ten are injured.
- On May 8, 1984, Soldier Denis Lortie, a federalist, enters National Assembly with the intent of killing René Lévesque and the deputies of the Parti Québécois. Due to a great amount of chance, he came in too early and killed 0 deputies, but still killed 3 other people and wounded 13. Unarmed employee René Jalbert negotiated with Lortie for several hours and convinced him to give up his gun and get arrested. Jalbert got decorated the next week.
- On December 6, 1989, Ecole Polytechnique massacre - Marc Lepine enters Ecole Polytechnique in Montreal, Quebec, Canada and murders 14 students as well as taking his own life for misogynistic and antifeminist reasons.
- On October 20, 2014, in the 2014 Saint-Jean-sur-Richelieu ramming attack, the radicalized Saint-Jean-sur-Richelieu, Quebec, Canada citizen Abu Ibrahim AlCanadi ran a soldier down and shot another. Couture-Rouleau was, in the aftermath, shot dead by an officer of the Sûreté du Québec.
- On October 22, 2014, Michael Zehaf-Bibeau opened fire at the National War Memorial in Parliament Hill Ottawa, Ontario, Canada. One soldier was shot. The suspect ran to the Parliament of Canada. The suspect was then engaged in a shoot out with security and police forces.
- On January 29, 2017 in the Quebec City mosque shooting, Alexandre Bissonnette, a Political science student at the University of Laval, opened fire in the Islamic Cultural Centre of Quebec City in Quebec City, Quebec, Canada and killed six worshipers.
- Maxime Brunerie's failed assassination attempt of Jacques Chirac
- January 2015 Île-de-France attacks in İlle-de-France
- November 2015 Paris attacks in Paris, France
- July 3, 2017 and November 6, 2018 assassination plots against Emmanuel Macron by far-righters
- Red Army Faction from 1970-1998
- National Socialist Underground from 2000-2006
- The murder of Walter Lübcke
- Years of Lead by far-right neo-Nazi/neo-fascist and far-left Communist/Marixist groups.
- 2018 Macerata attack by neo-Nazi Lega Nord member Luca Traini.
- New Zealand
- Wanganui Computer Centre bombing: November 1982, Anarchist Neil Roberts detonated a homemade bomb in a suicide attack on the New Zealand Police computer centre. Only Roberts was killed in the attack and while the building entrance doorway was destroyed the computer system was not damaged.
- Christchurch mosque shootings: March 2019, Australia-born Brenton Harrison Tarrant a self-described "Ethno-nationalist, Eco-fascist", "Kebab removalist", "racist" livestreams on Facebook Live the terrorist attacks on Al Noor Mosque and Linwood Islamic Centre in Christchurch, New Zealand after he wrote a manifesto titled The Great Replacement (named after the French far-right white genocide theory of the same name by writer Renaud Camus). 51 people are killed and 50 more are injured in New Zealand's deadliest mass shooting and terrorist attack.
- Norway attacks: July 2011, a right-wing extremist who spoke against Islam and immigration, Anders Behring Breivik was responsible for a car bomb explosion that killed 8 in Oslo and killing 69 at a summer camp on the island of Utøya in Norway.
- United Kingdom
- London Underground bombing July 2005 in London, United Kingdom
- Murder of Jo Cox in Birstall, West Yorkshire, United Kingom by Thomas Mair
- 2017 Finsbury Park mosque attack in Finsbury Park, London, United Kingdom by Darren Osbourne
- The neo-Nazi National Action
- United States
A non-exhaustive list of examples of U.S. attacks that have been referred to as domestic terrorism:
- 1966 University of Texas tower shooting
- 1969-1975 Attacks by The Weather Underground.
- 1973-1975 SLA activities and the 1974 shootout by Donald DeFreeze
- 1978-1999 Unabomber killings by Ted Kaczynski
- 1980-1985 Attacks by the Jewish Defense League.
- 1981 Muñiz Air National Guard Base attack by Boricua Popular Army
- 1983-1984 The Order/Bruder Schweigen activites such as the assassination of Jewish radio host Alan Berg in Denver, Colorado.
- 1994-1996 Aryan Republican Army criminal activities.
- 1995 Oklahoma City bombing at Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma by Timothy McVeigh
- 1996 Centennial Olympic Park bombing at Centennial Olympic Park, Atlanta, Georgia by Eric Robert Rudolph
- 1999 Los Angeles Jewish Community Center shooting at Granada Hills North Valley Jewish Community Center and Chatsworth in Los Angeles, California by Buford O. Furrow
- 1999 Columbine High School shooting and attempted bombing by Eric Harris and Dylan Klebold.
- 1999 The murders of Gary Matson and Winfield Mowder and burnings of Sacramento synagogues and abortion clinics in Happy Valley, California and Sacramento, California by Matthew and Tyler Williams
- 2002 Beltway sniper attacks in and around Washington, D.C. area by John Allen Muhammad and Lee Boyd Malvo
- 2008 Barack Obama assassination plot in Tennessee by neo-Nazi skinheads
- 2008 Knoxville Unitarian Universalist church shooting at the Tennessee Valley Unitarian Universalist Church in Knoxville, Tennessee by Jim David Adkinsson
- 2009 United States Holocaust Memorial Museum shooting at the United States Holocaust Memorial Museum in Washington D.C. by James von Brunn
- 2009 Fort Hood shooting at Fort Hood in Killeen, Texas by Nidal Hasan
- 2010 Austin suicide attack targeting the IRS at Building I Echelon office complex in Austin, Texas by Andrew Joseph Stack III
- 2013 Christopher Dorner shootings in the counties of Orange, Los Angeles and Riverside
- 2013 Boston Marathon bombing at Boylston Street and Boston Marathon in Boston, Massachusetts by Dzhkohar Tsarnaev and Tamerlan Tsarnaev.
- 2014 Overland Park Jewish Community Center shooting at the Jewish Community Center of Greater Kansas City and Village Shalom by Frazier Glenn Miller Jr.
- 2014 Isla Vista killings at the University of California, Santa Barbara (UCSB) campus in Isla Vista, California by Elliot Rodger
- 2015 Charleston church shooting at Emanuel African Methodist Episcopal Church in Charleston, South Carolina by Dylann Roof
- 2015 Lafayette shooting at Grand 16 movie theatre in Lafayette, Louisiana by John "Rusty" Russell Houser.
- 2015 Colorado Springs Planned Parenthood shooting at a Planned Parenthood clinic in Colorado Springs, Colorado by Robert Lewis Dear
- 2015 San Bernardino attack at the Inland Regional Center in San Bernardino, California by Rizwan Farook and Tashfeen Malik
- 2015 Chattanooga shootings at the Armed Forces Career Center and U.S. Navy Reserve center in Chattanooga, Tennessee by Muhammad Youssef Abdulazeez
- 2016 Orlando nightclub shooting at Pulse LGBT nighclub in Orlando, Florida by Omar Mateen
- 2016 shooting of Dallas police officers at Main Street and South Lamar Street in Dallas, Texas by Micah Xavier Johnson
- 2016 shooting of Baton Rouge police officers at Hammond Aire Plaza, B-Quik convience store and Hair Crown Beauty Supply in Baton Rouge, Louisiana by Gavin Eugene Long/Cosmo Setepenra
- 2017 Stabbing of Timothy Caughman at Hell's Kitchen in Manhattan, New York City, New York by James Harris Jackson
- 2017 Stabbing of Richard Collins III at the University of Maryland in College Park, Maryland by Sean Urbanski
- 2017 Congressional baseball shooting at the Congressional Baseball Game for Charity in Alexandria, Virginia by James Thomas Hodgkinson
- 2017 Fresno shootings at Motel 6 and downtown Fresno in Fresno, California by Kori Ali Muhammad
- 2017 Charlottesville car attack during the Charlottesville riots/Unite the Right rally at Downtown Mall in Charlottesville, Virginia by James Alex Fields
- 2017 Burnette Chapel shooting at the Burnette Chapel Church of Christ in Antioch, Tennessee by Emanuel Kidega Samson.
- 2018 October 2018 United States mail bombing attempts across various cities in the United States by Cesar Alteri Sayoc Jr.
- 2018 Murder of Blaze Bernstein at Borrego Park in Lake Forest, California by Samuel Woodard/Atomwaffen Division
- 2018 Jeffersontown Kroger shooting at a Kroger's grocery store in Jeffersontown, Kentucky by Gregory Alan Bush
- 2018 Tallahassee yoga studio shooting at Hot Yoga Tallahassee in Tallahassee, Florida by Scott Paul Beriele
- 2018 Pittsburgh synagogue shooting at Tree of Life - Or L'Simcha Congregation by Robert Bowers
- 2019 Christopher Paul Hasson's attempted assassination of Democrat, left-wing, and socialist politicians and journalists
- 2019 Escondido mosque fire and Poway synagogue shooting at Dar-ul-Arqam mosque and Chabad of Poway in Escondido, California and Poway, California by John T. Earnest
- 2019 Tacoma attack at a ICE detention center in Tacoma, Washington by Willem van Spronsen
- 2019 El Paso shooting at a Walmart store in El Paso, Texas by Patrick Crusius
- Domestic terrorism in the United States
- Jihadist extremism in the United States
- Domestic terrorism in Canada
- Gary M. Jackson, Predicting Malicious Behavior: Tools and Techniques for Ensuring Global Security (John Wiley & Sons, 2012), p. 235.
- Enders, Walter, Todd Sandler, and Khusrav Gaibulloev (2011). "Domestic versus transnational terrorism: Data, decomposition, and dynamics". Journal of Peace Research (3 ed.). 48 (3): 319–337. doi:10.1177/0022343311398926.CS1 maint: Uses authors parameter (link)
- "Wilner, Alex S., and Claire-Jehanne Dubouloz. "Homegrown terrorism and transformative learning: an interdisciplinary approach to understanding radicalization." Global Change, Peace & Security 22.1 (2010): 33-51".
- "p. 1. - Jerome P. Bjelopera and Mark A. Randol, American Jihadist Terrorism: Combatting a Complex Threat, (Washington, DC: Congressional Research Service, December 7, 2010)" (PDF). Retrieved 2013-07-19.
- 18 U.S.C. § 2332b
- Greg Myre (14 Aug 2017). "Why The Government Can't Bring Terrorism Charges In Charlottesville".
- "Non-State Conflict and the Transformation of War". E-International Relations.
- "Jason Ryan, Pierre Thomas, and Xorje Olivares, "American-bred Terrorism Causing Alarm for Law Enforcement," ABC News.com July 22, 2010". Abcnews.go.com. 2010-07-22. Retrieved 2013-07-19.
- "Toni Johnson, "Threat of Homegrown Islamist Terrorism," Council on Foreign Relations, December 10, 2010". Cfr.org. Retrieved 2013-07-19.
- "Peter Bergen and Bruce Hoffman, "Assessing the Terrorist Threat," Bipartisan Policy Center, September 10, 2010" (PDF). Retrieved 2013-07-19.
- Brian Michael Jenkins, "Terrorist Radicalization in the United States Since September 11, 2001," RAND Corporation, 2010
- Yager, Jordy (2010-07-25). "Jordy Yager, "Former intel chief: Homegrown terrorism is a 'devil of a problem,'" The Hill, July 25, 2010". Thehill.com. Retrieved 2013-07-19.
- "Brendan Carlin and Abul Taher, "Cameron plans to crack down on home-grown terrorism," gulfnews.com, June 6, 2011". Gulfnews.com. 2011-06-06. Retrieved 2013-07-19.
- Chalfant, Morgan (July 23, 2019) "FBI's Wray says most domestic terrorism arrests this year involve white supremacy" The Hill
- Spaaij, Ramón (2010). "The enigma of lone wolf terrorism: An assessment". Studies in Conflict & Terrorism. 33 (9): 854–870. doi:10.1080/1057610X.2010.501426.
- Springer, Nathan R. (2009). "Patterns of radicalization: Identifying the markers and warning signs of domestic lone wolf terrorists in our midst". Naval Postgraduate School (thesis).
- Turchie, Terry D.; Puckett, Kathleen M. (2007-01-01). Hunting the American Terrorist: The FBI's War on Homegrown Terror. History Publishing Company. ISBN 9781933909349.
- "Associated Press, "Congressional Panel on Homegrown Terrorism Divided on Discussion," March 10, 2011". Tennessean.com. Retrieved 2013-07-19.
- Marc Sageman, Leaderless Jihad: Terror Networks in the Twenty-First Century, (Philadelphia, PA: University Of Pennsylvania Press, 2008)
- "Hoffman, Bruce. "Rethinking terrorism and counterterrorism since 9/11." Studies in Conflict and Terrorism 25.5 (2002): 303-316".
- p. 33 - Edward McCleskey, Diana McCord, and Jennifer Leetz, “Underlying Reasons for the Success and Failure of Terrorist Attacks.” (Arlington, VA: Homeland Security Institute, June 2007) Archived July 19, 2011, at the Wayback Machine
- Dao, James (February 16, 2010). "A Muslim Son, a Murder Trial and Many Questions". The New York Times. Arkansas;Yemen. Retrieved June 23, 2010.
- Dao, James (January 21, 2010). "Man Claims Terror Ties in Little Rock Shooting". The New York Times. Archived from the original on 25 January 2010. Retrieved January 22, 2010.
- "Hoffman, Bruce, "Internet Terror Recruitment And Tradecraft: How Can We Address An Evolving Tool While Protecting Free Speech?," House Committee on Homeland Security, Subcommittee on Intelligence, Information Sharing, and Terrorism Risk Assessment, May 26, 2010" (PDF). Archived from the original (PDF) on December 5, 2010. Retrieved April 12, 2011.
- Schmitt, Eric (June 6, 2010). "Al Shabab Recruits Americans for Somali Civil War". The New York Times. Retrieved June 9, 2010.
- ""Radicalization in the West: The Homegrown Threat." (New York Police Department, 2007)" (PDF). Retrieved 23 November 2014. (pages 8-9)
- Security Weekly. "Scott Stewart, "Fanning the Flames of Jihad." STRATFOR (July 22, 2010)". Stratfor.com. Archived from the original on July 6, 2013. Retrieved 2013-07-19.
- "SLA: The shootout". Court TV. October 12, 2001. Archived from the original on August 15, 2007. Retrieved 2007-08-18.
Perry and Hall exited the house, but were shot by officers who concluded they were trying to kill police rather than surrender.
- Kären M. Hess, Christine Hess Orthmann & Henry Lim Cho, Introduction to Law Enforcement and Criminal Justice (12th ed.: Centgage, 2018), p. 453.
- Kären M. Hess, Christine H. Orthmann & Henry Lim Cho, Police Operations: Theory and Practice (6th ed.: Delmar Cengage Learning, 2013), p. 322.
- Greg Myre, Boston Bombings Point To Growing Threat of Homegrown Terrorism, NPR (April 20, 2013).
- Peter Forster & Thomas Hader, Combating Domestic Terrorism: Observations from Brussels and San Bernardino, Small Wars Journal (July 18, 2016).
- Chattanooga shooting a 'terror attack,' FBI Director James Comey says, Fox News (December 16, 2015).
- Matthew Grimson, David Wyllie & Elisha Fieldstadt, FBI says it probed Orlando shooting suspect Omar Mateen twice, NBC News (June 13, 2016).
- Bjelopera, Jerome P. (January 23, 2013). "American Jihadist Terrorism: Combating a Complex Threat" (PDF). Congressional Research Service.
- Cruickshank, Paul and Robertson, Nic (May 11, 2010). "Analysis: The spread of U.S. homegrown terrorism". CNN. Retrieved 2013-07-19.CS1 maint: Multiple names: authors list (link)
- Durodié, Bill (February 2008). "Home-Grown Nihilism: The Clash within Civilisations". Defence Academy of the United Kingdom.
- Nelson, Rick (January 22, 2010). "Homegrown Terrorism Fact Sheet". Center for Strategic and International Studies. Retrieved 2013-07-19.