Preventing Attacks Using Targeted Violence Manifestos

By Julia Kupper

A stock image of a man looking at a cellphone.

I’m Jared Cano, but you guys probably know who I am by now. For those of you retards who don’t know who I am, I’m the Freedom High School shooter in Tampa, Florida. Well, I will be in a couple months. I just thought I’d make some videos … so the government can’t just tell you  I’m some crazy, nutty, loony nut. ... My plan is to set a bomb here at point A, here at point B, point C, and point D. … The bombs blow at 7:26. … I’m going to walk into the parking lot and shoot anybody there.1

Cano uttered these words in a cell phone video describing a detailed plan to bomb his former high school and shoot students and staff as they escaped. Law enforcement successfully mitigated the threat before he could act, and he was later sentenced to 15 years in prison.2

This article argues that written and spoken communications authored and leaked by lone perpetrators like Cano who actively plan and prepare targeted violence can be utilized to prevent destructive attacks. Targeted violence refers to intended attacks by an offender who preselects one or more targets, such as people at a specific location in a public setting (e.g., school, workplace, concert).

Some of these attacks are driven primarily by personal grievances, rather than strict ideologies, and are also referred to as lone actor grievance-fueled violence.3 If ideology motivates a targeted violence attack, it is called terrorism. It is conducted by offenders who “primarily attack noncombatant populations and exploit the psychological impact of these attacks in their efforts to bring about change to the current political system”4 or to accomplish a desired societal order.

Ms. Kupper is a consulting forensic linguist and independent researcher in Los Angeles.

Ms. Kupper is a consulting forensic linguist and independent researcher in Los Angeles.

Both types of attacks are designed to inflict mass casualties, expected to reach a public audience, and generated to create fear and anxiety among a specific community.5 Authoring a manifesto is part of this orchestration.


Threat assessment and management increasingly deal with manifestos, yet there appears to be no clear definition of the term in an illicit context. The author and her research partner recently coined and defined the term targeted violence manifesto:

Written or spoken communications compiled by an author that plans and prepares to carry out a specific, targeted act of violence. To justify the attack, the perpetrator articulates written or recorded self-identified grievances, homicidal intentions, and/or extreme ideologies. Generally composed before the incident occurs, the writings or recordings sometimes express beliefs and ideas that violently promote political, religious, or social changes.6

Moreover, these narratives are often created for and accessible by a public audience in furtherance of inspiring its like-minded members and opposing groups to commit similar attacks (i.e., copycats).7


Targeted violence manifestos can appear in many forms and differ in scope, complexity, and preparation.

  • Short social media posts (e.g., Mohammed Saeed Alshamrani’s multiple tweets prior to opening fire at the Naval Air Station Pensacola in Florida in December 2019)8
  • Elaborate essay-style statements (e.g., Patrick Crusius’ five-page manifesto posted to 8chan before conducting a shooting at a Walmart in El Paso, Texas, in August 2019)9
  • Strategic action plans (e.g., Faisal Mohammad’s detailed roadmap, supply list, and phrases he planned to use during his stabbing attack at the University of California, Merced, in November 2015)10
  • Thought-provoking flyers (e.g., Christopher Monfort’s anti-authority flyers distributed a week before murdering police officer Timothy Brenton in Seattle in October 2009)11
  • Cell phone videos (e.g., Michael Zehaf-Bibeau’s explanation of his attack prior to his shooting at Parliament Hill in Ottawa, Canada, in October 2014)12

These communications can vary significantly in length. For instance, Robert Bowers, who conducted a mass shooting at a synagogue in Pittsburgh in October 2018, posted a message consisting of 26 words on Gab one hour before he committed his attack: “HIAS likes to bring invaders in that kill our people. I can’t sit by and watch my people get slaughtered. Screw your optics, I’m going in.”13 Conversely, Anders Breivik emailed a 1,500-page statement to 1,000 recipients a few hours before committing his attacks in Utøya and Oslo, Norway, in July 2011.14

Messages not considered targeted violence manifestos include autobiographical messages, lists of weapons and targets, private writings (e.g., personal journals, diary entries, poems, short stories), personal correspondence, and suicide notes.15


The author and her research partner conducted a recent study comparing 30 written and spoken manifestos composed by lone offenders who planned or committed targeted violence.16 The incidents took place in North America, Europe, and Oceania between 1974 and 2021 and involved shootings, bombings, stabbings, vehicle incidents, a hostage situation, and a plane crash.

Motivations for the attacks ranged from extreme ideologies to personal grievances. They involved race and ethnicity, anti-government and anti-authority postures, inceldom,17 jihad, idiosyncratic ideologies (i.e., mix of different belief systems), and misanthropy. Some perpetrators expressed paranoia or were acting purely on emotions, such as frustration, vengeance, and hate. The authors of the manifestos used these triggers, motivations, and grievances to explain and justify engaging in a violent attack. In terrorism-related cases, the writings or recordings usually incorporated extreme ideologies that called for political, religious, or social changes.

“Targeted violence manifestos can appear in many forms and differ in scope, complexity, and preparation.”

Some perpetrators openly admitted they were inspired by other attackers’ manifestos and occasionally copied text elements from them. For instance, John Earnest, who conducted a shooting at a synagogue in Poway, California, in April 2019, referenced content from a manifesto by Brenton Tarrant, who had committed a mass attack at two mosques in Christchurch, New Zealand, the previous month.

‘WHY WON’T SOMEBODY DO SOMETHING? WHY WON’T SOMEBODY DO SOMETHING? WHY DON’T I DO SOMETHING?’ — the most powerful words in his [Tarrant’s] entire manifesto.18

Further, the offenders discussed their intentions and strategies for the act of violence, including tactical advice on weapons and techniques to encourage others to commit similar attacks. The narratives addressed the preferred outcome of the event, such as the number of victims, reaction from the media or public, and aftermath (e.g., arrest, suicide, or suicide by cop).

These themes can indicate the author of a manifesto is ramping up to commit an act of violence.


In 2019, the FBI released a study of 52 lone terrorists who committed attacks in the United States between 1972 and 2015.19 The report found that 96% of the offenders produced writings or videos intended to be viewed by others, and of those, 88% published their communications before the event occurred20 — also known as leakage, an essential concept in threat mitigation and a critical tool for intervention.21



Some perpetrators leak their intent of a violent attack over various internet platforms to offer self-proclaimed motivations, gain recognition, signal belonging to a specific group, and/or spread extreme ideologies to an international audience.22

  • Social media (e.g., Noah Green’s several grievance-based Facebook posts before driving his vehicle into two police officers at a barricade outside the U.S. Capitol in Washington, D.C., in April 202123)
  • Online forums (e.g., John Earnest’s far-right motivated declaration on 8chan before conducting his attack24)
  • Personal websites (e.g., George Sodini’s blog demonstrating incel ideology, which was his motivation for targeting a fitness center in Bridgeville, Pennsylvania, in August 200925)

“The authors of the manifestos used these triggers, motivations, and grievances to explain and justify engaging in a violent attack.”

Broadcast Media

Other offenders forward their manifestos to mainstream media and newsrooms. For instance, Jiverly Wong sent a handwritten letter to a television station more than two weeks prior to committing an attack on an immigration center in Binghamton, New York, in April 2009.26

On Location

Some offenders bring their manifestos directly to the attack site. For example, Christopher Sean Harper-Mercer handed a student an envelope with a flash drive that contained his manifesto and several documents related to other school shooters seconds before opening fire at his former college in Roseburg, Oregon, in October 2015.27 When present, swift bystander reporting and/or law enforcement action can aid in targeted violence prevention.


Writings and recordings addressing ideologies and grievances without explicitly discussing violence are often available in the weeks, months, or years prior to a planned event. For instance, Sebastian Bosse posted several hate- and anger-filled writings and videos on his website in the years before conducting a school shooting in Emsdetten, Germany, in November 2006.28

Manifestos relating specifically to an imminent threat are often posted or sent shortly before the attack, offering limited time for intervention. For instance, Brenton Tarrant posted his manifesto and a link to the livestream of his attack on 8chan half an hour before the massacre.29 Two days before the incident, Tarrant tweeted far-right sentiments and pictures of weapons that would later be used in the attack.30

These messages can be identified via open-source research, online monitoring, or tips and leads from the public. Thus, intelligence, counterterrorism, and risk management units can use this information to detect harmful intent before an act of violence takes place. In addition, manifestos can be crucial after an incident occurs to assist in determining motivation.

Warning Indicators

Words, phrases, and sentences expressing direct and indirect threats of violence can assist in identifying specific warning indicators. In turn, they can aid in determining if a case should be prioritized and actively risk managed or only monitored.

The author’s study analyzing the language in manifestos identified several warning indicators, such as statements of fixation, identification, and last resort.31 These should be considered red flags of an impending attack, especially when seen in combination with each other.


Perpetrators often demonstrate preoccupation with a specific individual, group, or location. For example, Elliot Rodger, the shooter of the Isla Vista killings in Santa Barbara, California, in May 2014, was motivated by incel ideology.

All those girls I’ve desired so much, they would have all rejected me and looked down upon me as an inferior man if I ever made a sexual advance towards them while they throw themselves at these obnoxious brutes. I’ll take great pleasure in slaughtering all of you.32

“Words, phrases, and sentences expressing direct and indirect threats of violence can assist in identifying specific warning indicators.”


Many authors of manifestos desire to be a soldier or warrior and want to mobilize violence for a specific cause. Nikolas Cruz, responsible for the Stoneman Douglas High School shooting in Parkland, Florida, in February 2018, was motivated by personal grievances.

Hello, my name is Nik, and I’m going to be the next school shooter of 2018. My goal is at least 20 people with an AR-15 and a couple of tracer rounds. … It’s going to be a big event, and when you see me on the news, you’ll know who I am, he-he. You’re all going to die! Pew pew pew pew pew. Ah yeah, can’t wait.33

Last Resort

Some offenders decide they must take immediate, personal action to make changes that align with their ideologies or rectify their grievances when no one else will. For instance, Dylann Roof, who was racially and ethnically motivated, carried out a church shooting in Charleston, South Carolina, in June 2015.

I have no choice. I am not in the position to, alone, go into the ghetto and fight. I chose Charleston because it is most historic city in my state, and at one time had the highest ratio of blacks to Whites in the country. We have no skinheads, no real KKK, no one doing anything but talking on the internet. Well someone has to have the bravery to take it to the real world, and I guess that has to be me.34


In a tactical environment, the risk level of an emerging or active threat can be assessed by analyzing the language of a perpetrator’s targeted violence manifesto before the intended attack. These types of concerning communications can be leaked through various channels and appear in different formats. Nonetheless, such writings and recordings can be utilized to assess the presence — or absence — of early warning indicators. If red flags are detected, threat assessors should seek additional information to further identify if other behavioral indicators suggest the author is in the final stages of preparing for an act of violence.

“In a tactical environment, the risk level of an emerging or active threat can be assessed by analyzing the language of a perpetrator’s targeted violence manifesto before the intended attack.”

Ms. Kupper can be reached at

1 John Muller and Kevin Dolak, “Jared Cano: Cell Phone Video Reveals Teen’s Elaborate Plan to Blow Up School,” ABC News, November 20, 2012,; and “Jared Cano Cell Phone Videos,” Yeet, August 10, 2019, video,
2 Times Staff Writer, “Teen Accused of Freedom High Bomb Plot Sentenced to 15 Years,” Tampa Bay Times, January 22, 2013,
3 Justin Barry-Walsh, David James, and Paul Mullen, “Fixated Threat Assessment Centers: Preventing Harm and Facilitating Care in Public Figure Threat Cases and Those Thought to Be at Risk of Lone-Actor Grievance-Fueled Violence,” CNS Spectrums 25, no. 5 (April 2020): 630-637,; and J. Reid Meloy and Paul Gill, “The Lone-Actor Terrorist and the TRAP-18,” Journal of Threat Assessment and Management 3, no. 1 (2016),
4 David Webber et al., “Ideologies That Justify Political Violence,” Current Opinion in Behavioral Sciences 34 (August 2020): 107-111,
5 U.S. Department of Homeland Security, Strategic Framework for Countering Terrorism and Targeted Violence (Washington, D.C., 2019), 4,; and Los Angeles County Department of Mental Health, “Targeted Violence Prevention” (course, Joint Regional Intelligence Center, San Marino, CA, August 5, 2019).
6 Julia Kupper and J. Reid Meloy, “TRAP-18 Indicators Validated Through the Forensic Linguistic Analysis of Targeted Violence Manifestos,” Journal of Threat Assessment and Management 8, no. 4 (2021): 174-199,
7 Andrea Fancher, email message to William Theroux, October 4, 2021.
8 Mohammed Alshamrani (@M7MD_SHAMRANI), “O American people, I’m not against you for just being American, I don’t hate you because your freedoms, I hate you because every day you supporting funding. ... ” Twitter, December 6, 2019, 4:39 a.m.,
9 Ellyn Santiago, “FBI Investigating Possible Manifesto in El Paso Walmart Shooting,” Heavy, August 5, 2019,; and Patrick Crusius, “The Inconvenient Truth,” manifesto, August 3, 2019,
10 FOX26 News, “FBI Releases ‘Manifesto’ from 2015 UC Merced Stabbing,” FOX26 News, November 16, 2020,
11 Elisa Hahn, “CSI Testifies About Monfort’s Alleged Message to Police,” KING 5 News, January 26, 2015,
12 Rosemary Barton, “Zehaf-Bibeau Video: Room Holds Its Breath During Gunman’s Final Words,” CBC News, March 6, 2015,
13 Robert Bowers (@onedingo), “HIAS likes to bring invaders in that kill our people. I can’t sit by and watch my people get slaughtered. Screw your optics, I’m going in.” Gab, October 27, 2018,
14 Reuters Staff, “Factbox: Excerpts from 1,500-Page Norway Killer Manifesto,” Reuters, July 24, 2011,; and Karl Ove Knausgaard, “The Inexplicable: Inside the Mind of a Mass Killer,” New Yorker, May 18, 2015,
15 Fancher.
16 Kupper and Meloy.
17 “Incels, or ‘involuntary celibates,’ are young, heterosexual men who blame women and society for their own inability to form romantic or sexual attachments.” Anti-Defamation League, “Incels (Involuntary Celibates),” accessed December 8, 2021,
18 John Earnest, manifesto, April 27, 2019,
19 U.S. Department of Justice, Federal Bureau of Investigation, Lone Offender: A Study of Lone Offender Terrorism in the United States (1972-2015), Behavioral Threat Assessment Center, November 2019,
20 Ibid., 39.
21 J. Reid Meloy, “Identifying Warning Behaviors of the Individual Terrorist,” FBI Law Enforcement Bulletin, April 8, 2016,
22 Kupper and Meloy.
23 Nicholas Fandos et al., “Capitol Suspect Struggled Before Attack, but Motive Remains Unclear,” New York Times, April 3, 2021,
24 Georgia Wells and Ian Lovett, “‘So What’s His Kill Count?’: The Toxic Online World Where Mass Shooters Thrive,” Wall Street Journal, September 4, 2019,
25 ABC News, “George Sodini’s Blog: Full Text by Alleged Gym Shooter,” ABC News, August 5, 2009,
26 William Kates, “I Am Jiverly Wong Shooting the People,” NBC4 Washington, April 6, 2009,
27 Luke Hammill, “Oregon Shooting: Mathew Downing, ‘The Lucky One,’ Details Harrowing Day,” Oregonian, October 9, 2015,
28 Julia Jüttner, “German School Shooting: Armed to the Teeth and Crying for Help,” Spiegel International, November 21, 2006,
29 Jason Murdock, “8chan User Claiming to be New Zealand Shooter Posted ‘See You All in Valhalla’ Before Mosque Massacre,” Newsweek, March 15, 2019,
30 Gerry Doyle, “New Zealand Mosque Attacker’s Plan Began and Ended Online,” Reuters, March 15, 2019,
31 Kupper and Meloy.
32 CNN Staff, “Transcript of Video Linked to Santa Barbara Mass Shooting,” CNN, May 28, 2014,
33 Michael James, “Parkland’s Nikolas Cruz Made Chilling Videos Before Shooting: ‘You’re All Going to Die,’” USA Today, May 30, 2018,
34 Scott Neuman, “Photos of Dylann Roof, Racist Manifesto Surface on Website,” National Public Radio, June 20, 2015,