Extreme right perpetrators
Active shooter is an individual or a small group actively engaged in killing or attempting to kill people in a confined space or populated area. Some of the active shooter perpetrators, such as Nidal Hasan and Anders Behring Breivik, could easily be considered as terrorists, since their rage was also motivated by political objectives. An active shooter differs from a barricaded gunman, who poses a potential threat of injury or death to hostages, but is not in the process of actively causing death or injury. John Zawahri's shooting rampage was premeditated, given his extensive collection of armaments and his preparation for his attacks. He had a long history of encounters with law enforcement. According to Yaakov Rofe, an Israeli psychologist, his behavior likely stemmed from a state of stress and depression combined with a difficult financial situation and a history of previous failures.