RIVERDALE, Ga. -- A now former Riverdale police officer has been placed under arrest on charges of rape and sexual assault of a woman in custody, officials with the Georgia Bureau of Investigation said Wednesday.

Investigators said 36-year-old James Larry Robinson Jr. faces one count of each that stem from the GBI's investigation into the allegations of a female inmate.

The incident allegedly happened while the victim was being taken from Riverdale Police Department to the Clayton County Jail.

On Aug. 16, the Riverdale Police Department requested that the GBI conduct the criminal investigation. The charges were filed after the GBI consulted with the Clayton County District Attorney's Office.

Robinson turned himself in and was booked into the Clayton County Jail.

He was fired from the Riverdale Police Department on Tuesday. Officials say Robinson had only been hired by the department in March, 2016.

The GBI officially arrested Robinson, but he is being held in the Clayton County Jail. They released their official arrest report Thursday afternoon. 11Alive News is awaiting the booking photo of the officer.