THE RELIABILITY OF WITNESSES CAN DIFFER IN TERMS OF BOTH AGE AND SEX. OPERATIONAL DETECTIVES HAVE LONG APPRECIATED THE DIFFICULTIES ENCOUNTERED IN OBTAINING CORRECT DESCRIPTIONS FROM EYE WITNESSES IN THE EVENT OF A CRIME. IN CONDUCTING AN IDENTIFICATION PARADE, EVERY PRECAUTION SHOULD BE TAKEN TO EXCLUDE ANY SUSPICION OF UNFAIRNESS OR RISK OF ERRONEOUS IDENTIFICATION AND TO ASSURE THAT THE WITNESS' ABILITY TO RECOGNIZE THE ACCUSED HAS BEEN FAIRLY AND ADEQUATELY TESTED. BY THEIR VERY NATURE, IDENTIFICATION PARADES CAN NEVER BE MADE COMPLETELY ERROR-FREE REGARDLESS OF WHAT INSTRUCTIONS ARE GIVEN TO POLICE ABOUT THE WAY THEY SHOULD BE CONDUCTED AND NO MATTER WHAT SAFEGUARDS ARE INTRODUCED TO SEE THAT THEY ARE CARRIED OUT PROPERLY. THE PARADES DO, HOWEVER, CONSTITUTE A VALUABLE WEAPON FOR BRINGING CRIMINALS TO JUSTICE. FORMULAS ARE PRESENTED FOR DETERMINING THE VALUE OF INFORMATION GAINED FROM AN IDENTIFICATION PARADE. (DP)