THE STUDY SAMPLE INCLUDED 86 MALES CHARGED WITH SERIOUS SEX OFFENSES IN 1951 AND 122 MALES CHARGED WITH SERIOUS SEX OFFENSES IN 1961. THE FOLLOWUP PERIOD FOR POSSIBLE RECONVICTIONS WAS TO THE END OF MARCH. THE MAJORITY OF CASES INVOLVED UNLAWFUL SEXUAL INTERCOURSE WITH GIRLS UNDER 13 YEARS OF AGE, FOLLOWED BY CASES INVOLVING INCEST AND RAPE. OF THOSE CONVICTED, 160 OR 82 PERCENT WERE GIVEN CUSTODIAL SENTENCES. PERSONS ACQUITTED AND 12 OFFENDERS WHOSE FILES COULD NOT BE TRACED WERE DISREGARDED IN SUBSEQUENT ANALYSIS. OF THE REMAINING 184 CASES, 100 HAD NO PREVIOUS CONVICTIONS, 31 HAD ONE PREVIOUS CONVICTION, 17 HAD TWO PREVIOUS CONVICTIONS, AND 36 HAD THREE OR MORE PREVIOUS CONVICTIONS. TWENTY-EIGHT PERSONS PREVIOUSLY HAD COMMITTED PERSONAL VIOLENCE AND/OR SEXUAL OFFENSES. OFFENDERS GIVEN NONCUSTODIAL SENTENCES IN 1951 WERE FOLLOWED FOR OVER 22 YEARS, WHILE OFFENDERS GIVEN LONG TERMS OF IMPRISONMENT IN 1961 HAD COMPARATIVELY SHORT PERIODS AT RISK. A LIFE TABLE WAS CONSTRUCTED TO ESTIMATE THE LIKELIHOOD THAT MEN IN THE SAMPLE WOULD BE RECONVICTED FOR ANY STANDARD LIST OFFENSE DURING THE 23 YEARS OF FOLLOWUP. THE VALUE OF THE LIFE TABLE METHOD BECAME APPARENT WHEN CONSIDERING THE CUMULATIVE TOTAL RECONVICTED FOR THE SAMPLE (48 PERCENT). THE FIRST 32 CASES OF RECONVICTION FOR SEXUAL OR VIOLENT OFFENSES DURING THE FOLLOWUP PERIOD EXHIBITED THE FOLLOWING RANGE OF OFFENSES: INCEST, ATTEMPTED RAPE, UNLAWFUL SEXUAL INTERCOURSE, ATTEMPTED CARNAL KNOWLEDGE, INDECENT ASSAULT, GROSS INDECENCY, ATTEMPTED ROBBERY, AND GRIEVOUS ACTUAL BODILY HARM. THE MOST IMPORTANT ASPECT OF THE STUDY INVOLVES THE VALUE OF LONG TERM FOLLOWUP IN VIEW OF THE FACT THAT A SIZABLE PROPORTION OF OFFENDERS ARE RECONVICTED A LONG TIME AFTER THE USUAL FOLLOWUP PERIOD OF 3 TO 5 YEARS. SUPPORTING TABULAR DATA AND REFERENCES ARE PROVIDED. (DEP)