shooters. In most cases, the shooters did not express a fascination with weapons or explosives.

Although the attacker acted alone in at least two-thirds of the cases, they were influenced or encouraged by other students in almost half of the attacks. In more than three-quarters of the attacks, other students knew about the attack before it happened. Some knew exactly what was planned, while others only knew that something “big” or “bad” was going to happen.

In more than two-thirds of the cases, bullying played a key role in the attack. In these instances, the shooter felt persecuted, threatened, attacked, or injured by others before the outburst. Some of the attackers had experienced intense bullying and harassment for a very long period of time.

In more than three-quarters of the incidents, the attackers had difficulty coping with a major change to a relationship or a loss of status (e.g., a personal failure) prior to their school attack. More than half of the attackers had a history of feeling extreme depression and nearly three-quarters of the attackers had threatened or attempted to commit suicide prior to the incident.

School Shooter Threat Assessment

The National Center for the Analysis of Violent Crime of the Federal Bureau of Investigation (FBI) has also developed a model of threat assessment for school shooters by analyzing 18 school shooting cases (Federal Bureau of Investigation, 2000). The incidents involved both single and multiple offenders. Actual shootings occurred at 14 schools; in the remaining 4 cases, the student or students had planned and made significant preparations but were detected by law enforcement before the shooting took place. These 18 cases were supplemented by an unidentified number of cases in which the center was already preparing a threat assessment.

The FBI study described a process they call “leakage,” in which a student intentionally or unintentionally reveals clues to feelings, thoughts, attitudes, or intentions that may signal an impending act (Federal Bureau of Investigation, 2000). These clues can take the form of subtle threats, inappropriate jokes, boasts, or innuendos and can be either spoken or conveyed in stories, journal entries, essays, poems, songs, or drawings. Leakage is considered to be a cry for help and the most important clue that precedes the violent act.

The FBI’s findings focus on the personality traits of school shooters; their relationship with parents and the quality of parenting; social relationships at school, including relationships with deviant peers and the



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