Prosecutors are reviewing a police investigation into the parents of a three-year-old boy who fell into a gorilla enclosure at the Cincinnati Zoo last Saturday, prompting the killing of an endangered gorilla.
A statement on the website for Hamilton County Prosecutor Joseph Deters said the earliest he would conclude his review would be tomorrow.
Cincinnati police have said the child's parents and family were the target of the probe and not the operation or safety of the zoo.
Mr Deters' office did not return a call for comment beyond the statement.
Meanwhile, Cincinnati police have released the audio recording of the 911 call made by the mother of the young boy.
Just moments after the child fell into the gorilla enclosure on Saturday, his terrified mother called for help.
Listen: Emergency call by mother of boy who fell into the gorilla enclosure at Cincinnati zoo is released.https://t.co/b052G4vC83
— RTÉ News (@rtenews) June 2, 2016
Harambe, a 190kg Western lowland gorilla grabbed him, Cincinnati Zoo Director Thane Maynard told reporters.
The boy was with the 17-year-old gorilla for about ten minutes, during which he looked like he was protecting the child at times, while other times dragging him through the water.
The staff decided that the boy's life was in immediate danger and shot the animal dead.
A tranquiliser would have worked too slowly, the zoo said.
Both the parents and the zoo have been criticised for the incident.
