

Mass murders such as familicides where one member of a family kills all other members in the family home are not considered as lone actor shootings. the shootings occurred in a public situation.This still meets the academic definition of lone actor shooting, because the perpetrators carried out the killings without direction from anyone else

In some cases such as the Columbine High School massacre, two students shot and killed 12 students and one teacher.

The academic definition of lone actor mass shootings means they occur in a public setting and excludes the killing of multiple people if those deaths occur during the commission of other crimes, such as bank robberies or during gang warfare. Studies have found that some lone actor attacks are committed because of personal grievances and a desire for revenge, while others are acts of terrorism, intended to induce fear and influence the way people think. Lone actor attacks have become the subject of academic research. Although definitions vary, most databases require a minimum of four victims (including injured) for the event to be considered a mass murder. In other countries, knives are sometimes used to commit mass stabbings. In the United States, such attacks are usually committed with firearms. A lone wolf attack, or lone actor attack, is a particular kind of mass murder, committed in a public setting by an individual who plans and commits the act on their own.
