To increase an arrest rate of perpetrators by identifying perpetrators and facilitating the participation of police dogs because robbers of banks, convenience stores, taxis and the like are not easy to arrest and add to social unrest.

A spray 2 sprayed from a perpetrator discriminating spray 1 or a perpetrator incapacitating spray 1 characteristically uses a mixture most suitable for a bank, a convenience store, a taxi and the like. The spray 1, which is automatically or manually actuated, facilitates perpetrator identification.