Police investigating after a three-year-old boy entered a Cincinnati Zoo gorilla exhibit and was dragged around by a massive primate that was shot dead to protect him have said they are looking only at actions by the child's family.
Police said the investigation was unrelated to Saturday's shooting or safety of the Ohio zoo.
Speaking to The New York Post Cincinnati Police Department spokeswoman Tiffaney Hardy said her department is looking into the actions of the parents of the child on the day of the incident.
“The investigation is regarding the action of parents and family that led up to the incident and is not related to zoo operations,” said Hardy.
“We’re looking into the incidents that led up to the incident.”
A newly-released Cincinnati police report said the boy fell 15 feet into water in the Gorilla World exhibit and then played in it.
The western lowland gorilla named Harambe climbed down to the boy, picked him up in an apparent effort to protect him and carried him up into the enclosure.
The boy was alert and talking when rescued and had only minor scrapes on his head and knee, the report said.
The boy's parents have said he was doing well after his ordeal.
Some people have argued that there should be child endangering charges against the parents, while others want the zoo held responsible.
Meanwhile presumptive Republican presidential nominee Donald Trump said the zoo had little choice but to kill the 17-year-old gorilla.
Mr Trump, asked about the gorilla during a news conference in New York, referred to videos showing the animal at times appearing protective of the child, who got away from his mother and entered the gorilla's enclosure.
He said watching the gorilla with the boy was "almost like a mother holding a baby", but noted that the video also showed the gorilla dragging the boy through a shallow moat.
Mr Trump acknowledged that it was "a very tough call" but said the child's life was at stake.
The zoo has an open viewing area that was among the first of its kind and is now common in many zoos around the country.
The exhibit was at the forefront of zoos moving away from cages in favour of more realistic living environments and adopting a range of exhibits, from natural habitats behind glass walls to jungle-like settings separated from the public by hedges and bamboo fences.
While police are investigating what happened in Cincinnati and government inspectors are planning their own review, the zoo says it too will look at whether it needs to reinforce the barriers, even though it considers the enclosure more secure than what is required.
"The exhibit is safe, the barrier is safe," said zoo director Thane Maynard, who noted it was checked routinely by inspectors and the Association of Zoos and Aquariums, which also plans to investigate the incident.
The breach, the zoo director said, was the first time a visitor had entered Gorilla World, which opened in 1978 and was billed as the first "bar-less" outdoor gorilla habitat in the US.
A government inspection less than two months ago found no problems with the gorilla exhibit, but earlier inspections reported issues including the potential danger to the public from an incident in March involving wandering polar bears inside a behind-the-scenes service hallway.
Some critics have blamed the boy's parents for not keeping a close eye on the child and at least two animal rights groups say the is zoo responsible for the gorilla's death, saying that the barrier made up of a fence, bushes and a moat was inadequate.
Most gorilla exhibits around the country now have open-viewing areas, often protected by a combination of glass walls, mesh netting and moats.
Child safety expert Kimberlee Mitchell, who runs a childproofing business in southern California, said attractions needed to be made as safe as possible because many people dropped their guard at an amusement park or zoo.
But, she added, even an attentive parent could be distracted.
"It's unthinkable that a zoo exhibit would be created in such a way that a little three-year-old boy could climb in," she said.
"He shouldn't be able to get in there even with his mom's head turned."