U.S. Agriculture Department spokeswoman Tanya Espinosa said an investigation is continuing. "Fixed public exhibits housing nonhuman primates must have a barrier between the primary enclosure and the public in order to restrict physical contact between the public and the nonhuman primates".
On May 28, a 3-year-old boy slipped through the barrier and a hedge to fall 15 feet into the zoo's Gorilla World exhibit. Harambe pulled the boy along the shallow moat, then stood him up and appeared to inspect his clothes.
But according to a USDA spokesperson, anything that is documented on an inspection report is considered "noncompliance".
One of the members of the team decided the child was in "life-threatening danger" when the 17-year-old gorilla named Harambe was killed to save the child.
In addition to citing the barrier, the federal report also noted that zoo officials acted properly in their response procedure.
By the time the boy slipped into the cage on May 28, however, Espinosa said the barrier had begun to break down.
The Cincinnati Zoo has since redesigned the fence at the gorilla enclosure, making it six inches taller than before and covered in nylon mesh.
The federal investigation has not yet been closed and penalties may still be levied against the zoo, officials said.
In its 38-year history, the barrier system at Gorilla World has always been found compliant during USDA inspections, including one conducted in April of 2016.
The Department of Agriculture inspectors said in a report dated June 6 there had been "some slack" in wire cables in the barrier that could have been "manipulated to an eight-inch gap".
Animal welfare activists and other gorilla fans expressed anger at Harambe's death, and it became the subject of countless memes and popular culture references.
A statement from the family of the boy who fell into the enclosure said the "findings do not change anything for us".
The incident was recorded on video and became a sensation receiving broad global coverage and commentary, with controversy over the choice to kill Harambe.
The barrier was modified after the incident to "reassure the public", the zoo said.
Zoo Director Thane Maynard said the zoo will continue to work with authorities to ensure its exhibits meet or exceed standards. We very much appreciate the quick actions by the Cincinnati Zoo staff, and mourn with them the loss of Harambe.