Georgia Bureau of Investigation Director Vernon Keenan told the Atlanta Journal-Constitution Wednesday an arrest had been made but declined to release details.
It was not immediately known what charges were being brought. A news conference was scheduled at 1:45 p.m. Wednesday.
Jorelys Rivera was last seen Friday evening leaving a playground at her apartment complex.
Autopsy results showed the girl died of blows to the head and was stabbed and sexually assaulted before her body was placed in a trash bin at the complex.