The New York Times is doing a "Room for Debate" feature on the issue: Too Many Restrictions on Sex Offenders, or Too Few? Alejandro Leguízamo, a psychology professor, worries that that enforcement of sex offender regulations may vary by race. He is particularly concerned that the risk assessment process will yield racially disparate outcomes because the most common tool - Static-99 - may not work well with non-whites.
If true, you can stack this disparity on top of the racial skew I documented several years ago with respect to people subject to sexual offender community notification. It should be no surprise that a justice system displaying wildly disparate outcomes by race in all other respects would yield no different result when it comes to sex offenders.