Systems and methods for searching for lost moving objects such as children are disclosed. In some embodiments, the systems and methods initiate an autonomous, expanding electronic search by emitting a search activation signal from a search initiation device. The search activation signal may include the target tag identifier of a target tag conveyed by the moving object. Search devices detecting the target tag may generate a hit signal, which may be used to determine the location of the target tag. In some instances, focused human searching for the moving object may be initiated based on this determined location, and/or on location information included in one or more hit signals.