One of the biggest opportunities data from NIBRS jurisdictions provide is the possibility of looking at crimes against children under age 12, a segment of the population that is not covered by the extensive self-report crime victimization information that has been available from the NCVS. Although children younger than age 12 represent only a small percentage of all reported victims (3 percent of all crimes and 6 percent of crimes against persons), their crime profile is unusual (table 3). Sexual assault accounts for almost one-third of this preteen victimization, more than twice the proportion for older juveniles, and family offenders make up one-third of the offenders against this group, twice the proportion for older juveniles. The familial and sexual nature of the crimes underscores some of the challenges this victim group poses for law enforcement. Victim and family cooperation with law enforcement is often problematic, as is the need to mitigate victim distress and trauma.