- Gorilla killed in order to rescue 4-year-old who fell into its enclosure
- Activists have filed a federal negligence complaint against the zoo
- Zoo authorities earlier said exhibit was safe, exceeded required protocol
An animal rights activist group said on Tuesday it had filed a federal negligence complaint with the US Department of Agriculture against the zoo, seeking the maximum penalty of $10,000 following Saturday's killing of the 450-pound ape named Harambe.
"The failure of the Cincinnati Zoo to adequately construct this enclosure to protect both the public and the animal held prisoner there is a clear and fatal violation of the Animal Welfare Act," Stop Animal Exploitation Now said in its complaint letter to the USDA.
Mounting outrage over the shooting death of the Western lowland silverback, which is an endangered species, sparked more than 460,000 signatures on online petitions at Change.org, some demanding "Justice for Harambe" and urging police to hold the child's parents accountable.
Zoo officials were not immediately available for comment on either the negligence complaint or the police investigation but said on Monday the exhibit was safe and exceeded required protocols.
Authorities are taking a second look at the possibility of criminal charges in the incident after police initially said no one was charged.
"The incident at the Cincinnati Zoo involving the young child who fell into the gorilla enclosure is under investigation by the Cincinnati Police Department," Hamilton County Prosecutor Joseph Deters said in a statement. "Once their investigation is concluded, they will confer with our office on possible criminal charges."
Witnesses said the child had expressed a desire to get into the enclosure and he climbed over a 3-foot (1-meter) barrier, falling 15 feet into a moat. His mother on Facebook said he suffered a concussion and scrapes but was otherwise fine.
Zookeepers shot Harambe after the 17-year-old animal grabbed the boy and dragged him around. Thane Maynard, director of the Cincinnati Zoo & Botanical Gardens, on Monday stood by the decision to shoot the gorilla, saying he was not simply endangering the child but actually hurting him.
The Gorilla World exhibit has been closed since the incident and will reopen on Saturday.
Tanya Espinosa, a spokeswoman for the USDA's Animal and Plant Health Inspection Service, said the complaint from Stop Animal Exploitation Now had been received but that an investigation had not yet been opened.
A review of the USDA inspection reports showed the zoo was cited in March 2016 for failing to close two doors near a service hallway that allowed two polar bears to enter the area housing dangerous items including cleaners and electrical wires. The bears had to be tranquilized before they could be returned to their enclosure, the report said.
The zoo also was cited in November 2014 for deteriorating wood in two enclosures for horses and one for Eastern black and white colobus monkeys, the report said.
The USDA regulates zoos, circuses and marine mammal parks under the Animal Welfare Act, the only federal law that requires a minimum standard of humane treatment and care for animals in research, exhibition, transport and by dealers.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)