Background: This research analyzes active shooter and active aggressor attacks, comparing attack methods, criminal profiles, and defense and evacuation strategies. Methods: Incidents in the U.S.A. and Brazil are examined, with a focus on data related to age, number of victims, and weapon types used. The report differentiates active shooters (who use firearms) from active aggressors (who may employ other means, such as knives). Results: It discusses the influence of past events, including the Columbine massacre, and its global repercussions, which encompass attacks in Brazilian schools. Defense methods highlighted include protocols like Run, Hide, Fight, along with training for evacuation and containment. Statistics reveal that most shooters are young men and that attacks primarily occur in schools and public areas. Conclusion: Finally, the study underscores the importance of public policies for prevention, security training, and psychological support for victims and affected communities.