A controller for use in a supplemental response system can include an initiation module that receives a communication from a primary response system. The controller can also include an interpretation module that receives the communication from the initiation module and that interprets the communication to determine a description of attention required by the source. The controller can further include a locating module that identifies a target region based on the first location of the source, and that identifies the supplemental responding entity at a second location within the target region based on the description of the attention required by the source. The controller can also include a communication module that transmits a request to a communication system of the supplemental responding entity at the second location within the target region.