Underestimating Recidivism
Reliance on measures of recidivism as reflected through official criminal justice system data obviously omit offenses that are not cleared through an arrest or those that are never reported to the police. This distinction is critical in the measurement of recidivism of sex offenders. For a variety of reasons, sexual assault is a vastly underreported crime. The National Crime Victimization Surveys (Bureau of Justice Statistics) conducted in 1994, 1995, and 1998
indicate that only 32 percent (one out of three) of sexual assaults against persons 12 or older are reported to law enforcement.
A three-year longitudinal study (Kilpatrick, Edmunds, and Seymour, 1992) of 4,008 adult women found that 84 percent of respondents who identified themselves as rape victims did not report the crime to authorities. (No current studies indicate the rate of reporting for child sexual assault, although it is generally assumed that these assaults are equally underreported.) Many victims are afraid to report sexual assault to the police. They may fear that reporting will lead to the following:
further victimization by the offender;
other forms of retribution by the offender or by the offender's friends or family;
arrest, prosecution, and incarceration of an offender who may be a family member or friend and on whom the victim or others may depend;
others finding out about the sexual assault (including friends, family members, media, and the public);
not being believed; and
being traumatized by the criminal justice system response.
These factors are compounded by the shame and guilt experienced by sexual assault victims, and, for many, a desire to put a tragic experience behind them. Incest victims who have experienced criminal justice involvement are particularly reluctant to report new incest crimes because of the disruption caused to their family.
This complex of reasons makes it unlikely that reporting figures will change dramatically in the near future and bring recidivism rates closer to actual reoffense rates.
Several studies support the hypothesis that sexual offense recidivism rates are underreported. Marshall and Barbaree (1990) compared official records of a sample of sex offenders with "unofficial" sources of data. They found that
the number of subsequent sex offenses revealed through unofficial sources was 2.4 times higher than the number that was recorded in official reports. In addition, research using information generated through polygraph examinations on a sample of imprisoned sex offenders with fewer than two known victims (on average), found that these offenders actually had an average of 110 victims and 318 offenses (Ahlmeyer, Heil, McKee, and English, 2000). Another polygraph study found a sample of imprisoned sex offenders to have extensive criminal histories, committing sex crimes for an average of 16 years before being caught (Ahlmeyer, English, and Simons, 1999).
Although some sex offenders are unique from the general criminal population (e.g., many extrafamilial child molesters), others (e.g., many rapists) possess many of the same characteristics that are associated with recidivism of general criminal behavior.
Research demonstrates that while sex offenders are much more likely to commit subsequent sexual offenses than the general criminal population, they do not exclusively commit sexual offenses. Therefore, some aspects of intervention with the general criminal population may have implications for effective management of sex offenders. Quinsey (1998) has recommended that in the absence of definitive knowledge about effective sex offender treatment, the best approach would be to structure interventions around what is known about the treatment of offenders in general.
http://www.csom.org/pubs/recidsexof.html