WASHINGTON — (CNN) Cincinnati police are investigating the incident at the city’s zoo last weekend in which a child entered a gorilla enclosure, police spokeswoman Tiffaney Hardy said Tuesday.

A 3-year-old boy managed to get into the enclosure and was dragged across a moat by the 450-pound gorilla. After a 10-minute encounter, Cincinnati Zoo officials shot and killed the gorilla, named Harambe.

The boy was not seriously injured.

“After the review, we will determine if charges need to be brought forward,” Hardy said. ” If it is determined charges need to be brought forward, we would then discuss it with the Hamilton County prosecutor’s office.”

It was not immediately clear whether the investigation will focus on the zoo or the boy’s mother, who was with the boy at the time he slipped past a fence and tumbled into the moat.

Julie Wilson, spokeswoman for the prosecutor’s office, declined to provide a time line for how long the investigation might take.

Meanwhile the child’s mother, who works at a child care center for toddlers and preschoolers in Cincinnati, has been the target of much public anger after zoo officials felt forced to shoot the 17-year-old Harambe, an endangered western lowland silverback, to protect her son.

Some suggested the boy’s parents should be held criminally responsible for the incident. An online petition seeking “Justice for Harambe” earned more than 100,000 signatures in less than 48 hours.

“This beautiful gorilla lost his life because the boy’s parents did not keep a closer watch on the child,” the petition states.

Witnesses interviewed by CNN and its affiliates contended officials had little choice because it appeared the clamoring crowd was agitating the great ape, putting the boy in greater danger, even though it initially appeared Harambe was trying to protect the child.

The tragedy happened after the boy told his mother he was going to get into the moat, and the mother admonished him to behave before being distracted by other children with her, Kimberly Ann Perkins O’Connor told CNN.

“The little boy himself had already been talking about wanting to go in, go in, get in the water and his mother is like, ‘No you’re not, no you’re not,’ ” O’Connor said. “Her attention was drawn away for seconds, maybe a minute, and then he was up and in before you knew it.”

The zoo announced that it had performed a necropsy on Harambe.

One of their research doctors was able to extract and freeze Harambe’s genetic material but no other details or plans for Harambe’s remains were immediately available, said the zoo’s communications director Michelle Curley.