What percentage of rape reports are false?

This may seem like a straightforward question, but in fact determining the percentage of false rape reports is complex. In the Online Training Institute (OLTI) module, False Reports: Moving Beyond the Issues to Successfully Investigate Sexual Assault, it is clearly stated that a report of sexual assault can only be determined to be false based on the evidence from a thorough investigation:

The determination that a sexual assault report is false can only be made if the evidence establishes that no crime was completed or attempted. This evidence will only be available after a thorough investigation, not after only a preliminary investigation or initial interview with the victim.

When methodologically rigorous research is conducted based on this definition, estimates for the percentage of false reports converge around 2-8%.

  • For example, Dr. David Lisak and colleagues analyzed sexual assaults reported to a major Northeastern university over a 10-year period to determine the rate of false reporting. Of the 136 reports taken during that period of time, 8 reports, or 5.9% were found to be false (Lisak, Gardinier, Nicksa, & Cote, 2010).
  • In a study of sexual assault cases reported to the Los Angeles Police Department in 2008, researchers found that rate of false reports was 4.5% (Spohn, White, & Tellis, 2014).
  • In a multi-site study of 8 US communities involved in the “Making a Difference” (MAD) Project conducted by EVAWI, data were collected by law enforcement agencies for all sexual assault reports received in an 18-24 month period. Of the 2,059 cases that were included in the study, 140 (7%) were classified as false.
  • Statistics even appear to converge internationally. In an analysis of 2,643 sexual assault cases reported to British police, 8% were classified by the police department as false reports. Yet when researchers applied the official criteria for establishing a false allegation, this figure dropped to 2%. These criteria specified that there must be either “a clear and credible admission by the complainant” or “strong evidential grounds” (Kelly, Lovett, & Regan, 2005).

In reality, no one knows – and in fact no one can possibly know – exactly how many sexual assault reports are false. However, estimates narrow to the range of 2-8% when they are based on rigorous research of case classifications using specific criteria and incorporating various protections of the reliability and validity of the research.

Kelly, L., Lovett, J., & Regan, L. (2005). A Gap or a Chasm? Attrition in Reported Rape Cases. Home Office Research Study 293. Home Office Research, Development and Statistics Directorate.

Lisak, D., Gardinier, Nicksa, S.C., & Cote, A.M. (2010). False Allegations of Sexual Assault: An Analysis of Ten Years of Reported Cases. Violence Against Women, 16 (12), 1318-1334.

Spohn, C., White, C., & Tellis, K. (2014). Unfounding Sexual Assault: Examining the Decision to Unfound and Identifying False Reports. Law & Society Review, 48 (1), 161-192.