Story highlights Prosecutor: The mother was attentive, but the 3-year-old "just scampered off"

The Gorilla World exhibit at the Cincinnati Zoo will reopen Tuesday

(CNN) The mother of the 3-year-old boy who fell into a gorilla exhibit at the Cincinnati Zoo will not face charges, an Ohio prosecutor said Monday.

"By all accounts, this mother did not act in any way where she presented this child to some harm," Hamilton County Prosecutor Joseph Deters said.

"She had three other kids with her and turned her back. ... And if anyone doesn't believe a 3-year-old can scamper off very quickly, they've never had kids."

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After the boy slipped into the enclosure May 28, he had a 10-minute encounter with Harambe, a 450-pound gorilla. A witness told CNN the boy's mother was temporarily distracted by other children when the boy fell into the exhibit.

Harambe pulled the boy across a moat and was fatally shot by zoo personnel.