A woman who fatally stabbed a 3-year-old boy sitting in a grocery cart outside a supermarket attacked him and his mother in less than five seconds before walking away, police said.

Police said witnesses nearby had no time to stop the stabbing that investigators believe was random.

Officers arrested 32-year-old Bionca Ellis, of Cleveland, while she was walking from the parking lot with a kitchen knife in her hand on Monday, police said. She was charged with aggravated murder and was being held on a $1 million bond.

Police dashcam and body camera video show a bystander pointing police toward Ellis after the stabbing. Officers ordered her to the ground and handcuffed her without any resistance, the knife laying by her side.

Ellis was inside the Giant Eagle grocery in the Cleveland suburb of North Olmsted when she saw the boy and his mother near the front and followed them into the parking lot, said Sgt. Matt Beck, a detective with North Olmsted police.

The boy’s mother was about to load her groceries into her vehicle when Ellis ran at them with a knife, stabbing the boy twice, Beck said. The boy died at a hospital.

The county medical examiner identified the boy as 3-year-old Julian Wood. His mother, Margot Wood, was treated at a hospital for a stab wound to her shoulder, police said.

Calls to a listing for Ellis went unanswered. It was not clear whether she has an attorney who could comment on the allegations. She did not speak during a brief court appearance Tuesday.

Investigators said Ellis got the knife at a thrift store next to the Giant Eagle before she walked into the grocery.

Ellis had no known previous interactions with the mother and her son and she had no history of being violent, Beck said.