WATCH: Parent slugs 7-year-old boy in the gut for no reason in school hallway

Police are investigating a parent who was caught on video punching a child in the stomach for no apparent reason.

Surveillance video recorded at KIPP DC Spring Academy in Washington shows the adult casually walking by the 7-year-old boy, punching him in the gut and then walking away as the child slumps over in pain, reported WJLA-TV.

Lena McLean said her son, John, came home from school Wednesday and told her about the attack, and she asked the school for video evidence.

“You don’t bully a child, you don’t torment a child," McLean said. "I wouldn’t do that to you. I wouldn’t do that to none of your kids. I’ll feel much better when he is locked up.”

McLean said she's had previous positive interactions with the parent, whose name has not been released, and she doesn't understand why he would punch her son.

“You watched my son on that ground and you didn’t do nothing -- and all you could say to me is you was playing,” she said.

A police report has been filed, and the incident remains under investigation.

Watch this video report posted online by WJLA-TV: