A Thunder Bay woman is demanding an explanation after a teacher's aide at her son's school cut his long hair — an action her lawyer says is clearly assault while the Crown insists there are no grounds for charges.

CBC has agreed to the mother's request to remain anonymous.

The seven-year-old boy had chin-length hair before the incident last month. His mother said staff at McKellar Park Central Public School were aware her son was letting his hair grow so that he could take part in traditional First Nations dancing.

The mother told CBC News she was stunned when her son told her it was a teacher's assistant who lopped off 10 centimetres of his hair.

"I said, 'Why did she do this? Did she say anything?'" said the mother. "And he said, 'No, and after she cut my hair, she took me by the shoulders and forced me to stand in front of the mirror. She made me stand there and said look at you now.'"

Lawyer Julian Falconer is representing the family.

"We have a classic example of the vulnerabilities of a seven-year-old being taken advantage [of] by someone with a pair of scissors who lifted that child on a stool and proceeded to violate the child," Falconer said. "The question becomes how could the police and the Crown attorney's office turn a blind eye to this?"

Thunder Bay police took head shots of the child as part of their investigation of the incident and also interviewed the school principal, the teacher's assistant involved and the mother and boy, said police spokesman Chris Adams.

"The Crown got back to us and indicated that there were no grounds for criminal charges, and it wasn't in the public interest according to the Crown," he said.

A spokesperson for Lakehead Public School Board confirmed the "unfortunate incident" took place but declined to comment further.

The teaching assistant has been suspended, but the mother said that does not go far enough.