The corrections department said Rodriguez retired in August after he was approached about the investigation.
It's the latest allegation of abuse by prison officials at facilities in California. A 2003 federal law known as the Prison Rape Elimination Act created a "zero-tolerance" policy for sexual assault against inmates. But in 2018, another former correctional officer who worked at the Central California Women's Facility for more than a decade was fired for sexual misconduct.
An Associated Press investigation found that a high-ranking federal Bureau of Prisons official, who formerly worked at a women's prison in the San Francisco Bay Area, was repeatedly promoted after allegations that he assaulted inmates. Another investigation found a pattern of sexual abuse by correctional officers at the women's facility.
The state corrections department's news release does not specify the type of conduct that Rodriguez allegedly engaged in. But the state's allegations against Rodriguez come after lawyer Robert Chalfant filed two federal civil rights lawsuits in early December alleging Rodriguez raped two inmates, who are known in the suits as Jane Doe and Jane Roe.
Federal court records did not list an attorney for Rodriguez, and attempts by The Associated Press to reach him through phone numbers found in public records were unsuccessful. The lawsuits were first reported by The Sacramento Bee.
One of the lawsuits alleges that Rodriguez forced Jane Doe to perform oral sex on him and raped her in May. The other alleges Rodriguez started making sexually inappropriate comments about Jane Roe before harassing her, groping her on multiple occasions and eventually raping her in June.
Both lawsuits accuse prison officials of negligence, saying they failed to prevent the assaults even though Rodriguez developed a reputation among inmates as a predator.
One lawsuit also names the state corrections department as a defendant.
The district attorney's office did not immediately respond to an email seeking comment. But Madera County District Attorney Sally Moreno told the Sacramento Bee that her office received the results of the state's internal investigation last week. She said her office is still reviewing the information.
Sophie Austin is a corps member for the Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on undercovered issues. Follow Austin on Twitter: @sophieadanna