We discuss several aspects of the multimedia fuzzy controller (MFC), which can be regarded as an extension of fuzzy controllers to include multimedia rules and memberships. The practical application context is that of law enforcement technology. We show the important role of the MFC for human input controllers in replacing the numeric input of standard controllers with media input. We have shown that the two essential problems of the FMC are the measure of distances in multifeatured spaces and the input of the media instance to the controller. The latter problem has two possible solutions: searching through the media database or constructing media instances. The first approach has been investigated in connection with the creation of a synthetic lineup for eyewitness identification of suspects. We have given a prescription for engineering a synthetic lineup for practical cases of interest. We have also shown that the essentially novel characteristic of the media databases required by the MFC is their commensurability.