A Cincinnati police spokesperson told CNN Tuesday that their inquiry "is only regarding the actions of the parents/family that led up to the incident and not related to the operation or safety of the Cincinnati Zoo."

The investigation could lead to prosecution.

"After the review, we will determine if charges need to be brought forward," police spokesperson Tiffaney Hardy told CNN. "If it is determined charges need to be brought forward, we would then discuss it with the Hamilton County prosecutor's office."

The boy's mother was allegedly with him when he fell through the fence and into the gorilla enclosure.

The zoo itself will be investigated further by the Association of Zoos and Aquariums and the U.S. Department of Agriculture.

"We'll of course be taking a closer look at that working with Cincinnati to figure out what happened and make sure we can firm that up so it doesn't happen again," AZA spokesperson Rob Vernon told CNN.

The USDA has found the zoo in violation of the Animal Welfare Act nine times in the past three years, according to a CNN investigation, but none of those breaches in compliance were relating to the gorilla enclosure. The USDA reports that two investigations were due to health concerns and that the other seven were similarly resolved. The body will investigate the gorilla incident but did not provide a timeline for that investigation.