Mass Shooters Often Reveal Their Plans First, New Study of 483 Attacks Finds

One of the most troubling paradoxes in American violence research is that mass shooters frequently tell people what they intend to do before they do it, and the attacks happen anyway. Some perpetrators engage in what threat assessment experts call leakage, signaling their interest in mass violence to an intimate partner, family member, friend, acquaintance, or online audience. Others make direct threats to the very people they later target. A family mass shooter was overheard telling his estranged wife three months before he murdered her and five children that if she did not quit, he would kill her and the others. A felony shooter told friends he wanted to rob and possibly kill someone days before he gunned down four people at a residence. A public shooter who killed 17 victims at a school posted on Instagram that he wanted to die fighting and shoot people with his AR-15. A new study has now systematically measured how often these warnings occur, who receives them, whether anyone reports them, and what the criminal justice system does when it hears them.

The research, published in the American Journal of Criminal Justice by Jason R. Silva of William Paterson University and Adam Lankford of the University of Alabama, is the most comprehensive assessment of its kind to date. The authors examined every United States mass shooting from 2000 to 2023 in which four or more victims were killed, a total of 483 incidents. Drawing primarily on a National Institute of Justice funded mass shooting database compiled by Jillian Turanovic and colleagues and updated through 2023, the team verified and supplemented the records using seven other open-source datasets, The Violence Project database, official documents such as court records and government reports, and extensive news coverage. Official records were located for 49 percent of cases, and information was corroborated across multiple sources wherever possible, with official documentation given precedence when accounts differed. Three researchers independently reviewed every case for evidence of pre-attack communication, and the final coding decisions were unanimous after discussion and third-party review of any contested cases.

The central distinction the researchers drew is conceptually important. Leakage refers to violent intent communicated to a third party, such as when person A tells person B about an interest in harming person C. A threat refers to violent intent communicated to the potential victim directly. The team also coded whether perpetrators revealed a specific interest in committing a mass killing, or only a general interest in violence such as homicide, along with the mode of communication, the type of recipient, whether the public reported the information, and whether the criminal justice system responded. In total, 197 of the 483 mass shootings, or 41 percent, were preceded by the perpetrator revealing violent intent through leakage or threats.

The type of mass shooting mattered enormously. Public mass shootings, those occurring in populated locations with victims chosen at random or for symbolic value, showed by far the highest rates of pre-attack communication. Leakage or threats preceded 71 percent of public mass shootings, with leakage occurring in 56 percent of cases and threats in 42 percent. By contrast, leakage and threats were less common among family mass shootings and least common among felony mass shootings, those connected to underlying criminal activity such as robbery, gang violence, or drug deals. In fact, family mass shooters were the group most likely to have never leaked, threatened, or discussed their violent intent with anyone, a pattern found in 61 percent of those cases. Notably, the researchers’ hypothesis that family and felony shooters would favor direct threats over leakage was not supported. Public shooters exceeded the other subtypes on every measure of pre-attack communication, largely because they were far more likely to reveal a specific interest in committing a mass killing, which occurred before 35 percent of public shootings but only 8 percent of family shootings and 2 percent of felony shootings.

Why would perpetrators deliberately sabotage the secrecy their attacks require? The study tested three theories using logistic regression models that controlled for the incident year, the volume of news coverage, and the availability of official records. The first is criminal propensity, rooted in Gottfredson and Hirschi’s general theory of crime, which holds that some individuals are so prone to risk-taking that the long-term consequences of talking about violence seem trivial. The second is the cry for help theory, adapted from suicidality research, which suggests that some perpetrators consciously or unconsciously wish to be stopped or rescued before committing acts that will almost certainly end in their death or imprisonment. The third is attention-seeking, grounded in Merton’s anomie theory, which proposes that individuals who lack legitimate means to attain valued goals such as recognition may resort to extreme or provocative statements.

All three theories received strong empirical support. When leakage and threats were analyzed as a composite measure, prior arrest records and histories of domestic violence, markers of criminal propensity, mental health problems and suicidal ideation, markers of a cry for help, and fame-seeking and ideological motives, markers of attention-seeking, were all significantly associated with pre-attack communication. When the behaviors were disaggregated, an instructive pattern emerged. Mental health problems, fame-seeking, and ideological motives predicted leakage specifically, while prior arrests, domestic violence history, mental health problems, and suicidal ideation predicted direct threats. The authors suggest this split makes intuitive sense: attention-seeking individuals may recognize that leaking to a third party garners attention without the added risk of making a threat that is more likely to be reported, whereas individuals with criminal propensity may care less about risks and may be accustomed to using threats coercively from past behavior.

The study also traced precisely where prevention efforts break down, and the results point more toward the public than the system. Of the 197 shootings involving leakage or threats, 54 percent were reported by the public before the attack, meaning nearly half went unreported. Yet when reports were made, 83 percent produced a formal criminal justice response, usually involving law enforcement being dispatched or the eventual perpetrator being interviewed or investigated. The attrition varied sharply by subtype. Public mass shootings were reported most often, at 61 percent of cases with leakage or threats, but those reports were least likely to trigger a response, at 70 percent. Felony mass shootings were reported only 20 percent of the time, though when they were reported, the criminal justice system responded in every single case. Family mass shootings followed a similar pattern, with reports producing a response 98 percent of the time. Even when responses occurred, escalation to arrest happened in only 21 percent of cases with leakage or threats, and incarceration in only 6 percent.

Perhaps the most counterintuitive finding concerns what motivates people to report. The researchers had hypothesized that fear of retribution would suppress reporting when shooters had prior arrests or histories of domestic violence, and that perceived attention-seeking behavior would likewise dampen reports. Both predictions failed. Shooters who directly threatened their victims were reported 71 percent of the time, compared with 48 percent for those who merely leaked, and 80 percent when both occurred. Perpetrators with prior arrest records, domestic violence histories, mental health problems, or pre-attack suicidal ideation were all reported at or above average rates. Fame-seeking shooters were reported 74 percent of the time, well above the 54 percent baseline. The authors conclude that public uncertainty about whether someone is genuinely dangerous, rather than fear of the dangerous person, appears to be the greatest barrier to reporting. Clearer signals, specific interest in mass violence, communication through multiple modes or to multiple recipients, and the expression of both leakage and threats, all raised reporting rates significantly, sometimes to 73 or 78 percent.

Only one hypothesis about reporting was confirmed in the unexpected direction: ideologically motivated shooters were reported less often than average, at 46 percent. The researchers suggest that members of the public may struggle to differentiate between people who intend to commit ideologically driven attacks and others who hold extremist views but are not violent, a challenge that even professional threat assessors face, since radicalized beliefs are themselves a weak predictor of attacks. Overall, the pattern aligns closely with the classic bystander effect described by Latané and Darley, in which diffusion of responsibility, pluralistic ignorance, and evaluation apprehension lead people to assume someone else will act or that the situation is not truly an emergency. The authors recommend that law enforcement agencies educate the public about evidence-based warning signs, encourage reporting even when people are uncertain, provide easy and anonymous reporting channels, and publicize success stories showing how community members’ reports helped avert violence. The findings suggest that while it may be impossible to prevent all mass shootings, a substantial share of them broadcast their intentions in advance, and the greatest room for improvement lies in convincing ordinary bystanders that what they are hearing is worth taking seriously.

Subject of Research: Pre-attack leakage, threats, public reporting, and criminal justice responses in U.S. mass shootings

Article Title: A Comprehensive Assessment of Leakage, Threats, Public Reporting, and Responses to Reports among Public, Family, and Felony Mass Shootings

Article References: A Comprehensive Assessment of Leakage, Threats, Public Reporting, and Responses to Reports among Public, Family, and Felony Mass Shootings. (n.d.). https://doi.org/10.1007/s12103-026-09946-8

Image Credits: AI Generated

DOI: 10.1007/s12103-026-09946-8

Keywords: mass shootings, leakage, threats, violence prevention, threat assessment, criminal justice, bystander effect, public reporting, criminology, fame-seeking, suicidal ideation, open-source research