The word `` missing '' should be enough and important ; the alert ( s ) system in place such as the Amber/silver provide an additional emergency notification seeking the public 's help . Monica Caison : « Caison : Many missing persons who have been missing for a long time are not found . She says the old `` knock and tell '' method can make the difference in finding someone . Caison : Communities can do more to assist law enforcement in investigations .
Monica Caison : « Caison : Many missing persons who have been missing for a long time are not found . She says the old `` knock and tell '' method can make the difference in finding someone . Caison : Communities can do more to assist law enforcement in investigations .