Sex offender registries were designed to protect the public from convicted sex offenders and future sexual violence. This study determines the percentage of clients seen at a sexual assault agency whose attacker was on the registry at the time the attack occurred. According to case files, only 3.7% of the identified offenders could possibly have been identified as a registered sex offender at the time of the attack. While considering the limitations of this methodology, the findings highlight a significant limitation of registries and support the idea that registries cannot be relied on exclusively to prevent sexual abuse.