San Diego County Sheriff's officials failed to investigate at least seven reported sexual assaults at the Otay Mesa immigration detention center in 2025, handing that authority instead to the private prison contractor that runs the facility, records obtained by CalMatters reveal.Under a 2020 memorandum of understanding between the Sheriff's Department and CoreCivic, Detention Center Warden Christopher LaRose has authority to decide whether to investigate rape allegations at the facility — which currently houses just under 1,500 federal immigration detainees, most of whom have not been convicted of any crime.CalMatters obtained the memorandum through a California Public Records Act request after reporting on seven alleged rapes and four attempted sexual assaults at the facility. A sheriff's spokesperson confirmed the agency was not investigating those cases but said additional records could not be released because they were part of 'a law enforcement investigation' — a seemingly contradictory response.CoreCivic, the nation's largest for-profit prison contractor, manages Otay Mesa under a contract with the Department of Homeland Security and ICE. The company states it has a 'zero tolerance' policy against sexual abuse, and a 2022 audit found the facility met federal prevention standards. Representatives did not respond to requests for comment.San Diego County Board of Supervisors Chair Terra Lawson-Remer said she plans to question Sheriff Kelly Martinez about the matter at an upcoming hearing on ICE transfers from county jails. The county is also in the midst of a separate legal battle with CoreCivic over a blocked public health inspection at the facility.'We're horrified but not surprised,' said Susan Beaty, senior attorney with the California Collaborative for Immigrant Justice. 'Local and state enforcement agencies have a responsibility to use their power to protect the rights of Californians in detention.'