To provide a security system, having a high security preparative effect and capable of improving response for determining a suspicious person, by collecting face feature data on the suspicious person in a community, deducing crime preparative conduct from the collected data, estimating a notable community for the suspicious person, and performing appropriate security activities.

The security system comprises a terminal device 1 and a management device 2. The terminal device 1 collates the face feature data created by extracting features of the face part of a photographed image, with face feature data having been stored in a storage part of the terminal beforehand, and transmits the face feature data to the management device 2 based on the result of the collation. The management device 2 collates the face feature data having been stored in a management storage part beforehand with the face feature data transmitted from the terminal device 1, determines crime preparative conduct from the collation, and performs warning, notification, or the like.