, in video and source data database 509. In some implementations, the video stream is stored on a server distinct from server system 164. In some implementations, after a motion start is detected, the relevant portion of the video stream is retrieved from storage e. g. , from video and source data database 509. In some implementations, the event identification process includes segmenting the video stream into multiple segments then categorizing the event candidate within each segment. In some implementations, categorizing the event candidate includes an aggregation of background factors, entity detection and identification, motion vector generation for each motion entity, entity features, and scene features to generate motion features for the event candidate. In some implementations, the event identification process further includes categorizing each segment, generating or updating an event log based on categorization of a segment, generating an alert for the event based on categorization of a segment, categorizing the complete event, updating the event log based on the complete event, and generating an alert for the event based on the complete event. In some implementations, a categorization is based on a determination that the event occurred within a particular zone of interest. In some implementations, a categorization is based on a determination that the event candidate involves one or more zones of interest. In some implementations, a categorization is based on audio data and/or audio event characterization.