A computer-implemented method to guide a dispatcher when communicating vocally with a caller via a communication device regarding an incident involving an active assailant and for dispatching an emergency dispatch response to the incident, the computer-implemented method comprising: initiating an emergency police dispatch protocol and a new case to record information received from the caller; presenting, on a dispatch center computer device (106, 130), a pre-scripted interrogation comprising a plurality of preprogrammed inquiries for the dispatcher to ask the caller; automatically, without dispatcher action, shunting from the emergency police dispatch protocol to an active assailant protocol immediately upon receiving indication of an active assailant in order to systematically obtain a description of the incident involving the active assailant, wherein the description of the incident comprises caller responses to the plurality of preprogrammed inquiries, and wherein the preprogrammed inquiries of the pre-scripted interrogation include: asking what happened, asking what type of weapons are involved, asking if the caller is on scene with the active assailant, and asking whether the caller can safely evacuate/leave the building/area; receiving, on the dispatch center computer device, dispatcher-entered input representative of caller responses to the preprogrammed inquiries of the pre-scripted interrogation; determining automatically on the dispatch center computer device a determinant value from one of a plurality of pre-established determinant values based on dispatcher-entered input representative of caller responses to one or more of the preprogrammed inquires including the caller response as to the type of weapon; generating pre-arrival instructions for the caller based on the caller response as to safe evacuation; and automatically ending the new case when a caller response indicates that the caller is not on scene with the active assailant. initiating an emergency police dispatch protocol and a new case to record information received from the caller; presenting, on a dispatch center computer device (106, 130), a pre-scripted interrogation comprising a plurality of preprogrammed inquiries for the dispatcher to ask the caller; automatically, without dispatcher action, shunting from the emergency police dispatch protocol to an active assailant protocol immediately upon receiving indication of an active assailant in order to systematically obtain a description of the incident involving the active assailant, wherein the description of the incident comprises caller responses to the plurality of preprogrammed inquiries, and wherein the preprogrammed inquiries of the pre-scripted interrogation include: asking what happened, asking what type of weapons are involved, asking if the caller is on scene with the active assailant, and asking whether the caller can safely evacuate/leave the building/area; asking what happened, asking what type of weapons are involved, asking if the caller is on scene with the active assailant, and asking whether the caller can safely evacuate/leave the building/area; receiving, on the dispatch center computer device, dispatcher-entered input representative of caller responses to the preprogrammed inquiries of the pre-scripted interrogation; determining automatically on the dispatch center computer device a determinant value from one of a plurality of pre-established determinant values based on dispatcher-entered input representative of caller responses to one or more of the preprogrammed inquires including the caller response as to the type of weapon; generating pre-arrival instructions for the caller based on the caller response as to safe evacuation; and automatically ending the new case when a caller response indicates that the caller is not on scene with the active assailant.