Reporting is Important

Get connected to support services:  If you are a survivor of sexual violence, dating violence, domestic violence, or stalking, reporting the incident will help you access many services to support you through the healing process, including medical and counseling services, academic and housing accommodations, and assistance in pursuing a complaint on or off-campus, should you wish to do so.
Regain a sense of personal power, control and safety: If you are a survivor, reporting the crime can help you regain a sense of personal power and control and can also help to ensure the safety of other potential victims. 
Protect the campus from repeat offenders: Reporting sexual violence is critical to ensuring the survivor’s future safety and the welfare of the college community. Research indicates that, while most men are not rapists, men who commit acts of sexual violence are likely to have committed similar crimes in the past and/or intend to commit similar crimes in the future. According to one researcher, 90% of rapes that occur on college campuses are committed by serial rapists.[1] Reporting helps to protect individuals and communities against these repeat offenders. 
Reporting without pursuing a complaint: If a survivor reports an incident of sexual violence, dating violence, domestic violence, or stalking, s/he does not have to pursue formal complaints on campus or criminally.

[1] Shapiro, Joseph (March 4, 2010). "Myths That Make It Hard To Stop Campus Rape." NPR. Cf. the research of David Lisak, including, Lisak, David; Miller, Paul M. (February 2002). "Repeat rape and multiple offending among undetected rapists". Violence and Victims 17 (1): 73–84.