"In 2018, correctional administrators reported 27,826 allegations of sexual victimization in prisons, jails, and other adult correctional facilities (figure 1). Of those allegations, 1,673 were substantiated after investigation. The number of allegations rose 180% from 2011 to 2015, which was partly attributable to correctional authorities’ response to the 2012 release of the National Standards to Prevent, Detect, and Respond to Prison Rape. From 2015 to 2018, the number of allegations increased more slowly (14%). During 2016-18, the majority of allegations involved staff sexual victimizations of inmates (56%), but most substantiated incidents involved inmate sexual victimizations of other inmates (55%)."

Source

Emily D. Buehler, PhD, Sexual Victimization Reported by Adult Correctional Authorities - 2016-2018," US Dept. of Justice, Bureau of Justice Statistics, NCJ 255356, June 2021.