THE STREET CRIME UNIT (SCU) WAS ORGANIZED IN 1971 TO AUGMENT TRADITIONAL POLICE ROLES OF UNIFORMED PATROL AND CRIMINAL INVESTIGATION. OFFICERS IN THE SCU DO NOT DETER CRIME BY THEIR PRESENCE. RATHER, THEY USE A TECHNIQUE OF 'INVISIBLE POLICE OMNIPRESENCE' FOR LAW ENFORCEMENT. BY BLENDING INTO THE COMMUNITY AND ASSUMING THE APPEARANCE OF A POTENTIAL CRIME VICTIM, SCU OFFICERS PLAY A UNIQUE ROLE. UNORTHODOX TACTICS OF ATTRACTING CRIMINALS TO POLICE DECOYS HAVE RESULTED IN A HIGH RATE OF FELONY CONVICTIONS FOR THE SCU. OVER 85 PERCENT OF PERSONS ARRESTED BY THE UNIT HAVE BEEN CONVICTED. NO SINGLE METHOD OF OPERATION IS ALWAYS SUCCESSFUL FOR THE UNIT, WHICH ONLY FUNCTIONS IN NEIGHBORHOODS WITH THE HIGHEST CRIME RATES. OFFICERS, HOWEVER, ARE ENCOURAGED TO USE THEIR IMAGINATION AND DEVELOP ALTERNATIVE METHODS THAT WILL RESULT IN VALID ARRESTS WHILE NOT POSING UNDUE DANGER TO THEMSELVES. EVERY DECOY RELIES ON AT LEAST TWO BACKUP OFFICERS WHO OBSERVE THE CRIME AND MAKE THE ACTUAL ARREST. THE SCU ALSO USES A SERIES OF NONDESCRIPT VEHICLES, INCLUDING VANS AND INCONSPICUOUS TAXIS. HEADBANDS ARE WORN BY SCU OFFICERS TO PERMIT THEIR IDENTIFICATION BY FELLOW POLICE OFFICERS. THE COMMUNICATION SYSTEM OF THE SCU IS BASED ON THE TWO-CHANNEL PORTABLE RADIO BUT, BECAUSE OF THE SIZE OF PORTABLE UNITS, DECOY AND BACKUP OFICERS RELY HEAVILY UPON HAND SIGNALS FOR COMMUNICATION DURING ACTUAL DECOY OPERATIONS. PHOTOGRAPHS ARE INCLUDED. (DEP)