What are the warning signs for someone planning a mass casualty event?
Early identification of potential threats can help prevent tragedies. Some warning signs that may indicate a person could pose a risk include:
- Obsessive interest in weapons or violent media
- History of aggression or violent behavior
- Social withdrawal or isolation from peers
- Expressions of hopelessness or desire for revenge
- Threatening statements or behaviors
- Sudden decline in personal or academic functioning
Proximal Warning Behaviors:
1. Pathway Behavior
- Concrete steps toward planning an attack; researching weapons, target locations, or security measures.
- Conducting reconnaissance or surveillance of the intended site.
- Testing weapons or practicing with them.
2. Fixation
- Increasingly obsessive focus on a person, group, ideology, or perceived grievance.
- Consuming large amounts of related media, often to the exclusion of other interests.
3. Identification
- Adopting the identity of a warrior, avenger, or previous attacker.
- Using nicknames, imagery, or symbols associated with violence.
- Expressing admiration for prior shooters.
4. Novel Aggression
- Engaging in new acts of violence or aggression not seen in the person’s past behavior.
- Potential physical assaults, cruelty to animals, or property destruction.
5. Energy Burst
- Sudden increase in activity related to the plan; acquiring weapons, training more frequently, visiting possible target sites repeatedly.
- Can also involve rapid completion of personal affairs (e.g., paying debts, giving away possessions).
6. Leakage
- Communicating intent to do harm to a third party - in person, online, or through writing.
- May be direct (“I’m going to make them pay”) or indirect (“They’ll be sorry soon”).
- Often appears on social media before an attack.
7. Last Resort Behavior
- Statements or actions that signal desperation or a belief that there is no way out except through violence.
- “I have no other choice,” “This is the only way to fix it.”
8. Directly Communicated Threat
- Explicitly telling a person or institution they will be attacked. While some attackers give no direct warning, a notable subset do.
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