One of the most controversial—and least understood—issues in the area of sexual violence is the prevalence of false reports of rape. Estimates of the rate of false reports vary widely, which reflects differences in way false reports are defined and in the methods that researchers use to identify them. We address this issue using a mixed methods approach that incorporates quantitative and qualitative data on sexual assault cases that were reported to the Los Angeles Police Department (LAPD) in 2008 and qualitative data from interviews with LAPD detectives assigned to investigate reports of sexual assault. We found that the LAPD was clearing cases as unfounded appropriately most, but not all, of the time and we estimated that the rate of false reports among cases reported to the LAPD was 4.5 percent. We also found that although complainant recantation was the strongest predictor of the unfounding decision, other factors indicative of the seriousness of the incident and the credibility of the victim also played a role. We interpret these findings using an integrated theoretical perspective that incorporates both Black's sociological theory of law and Steffensmeier, Ulmer, and Kramer's focal concerns perspective.