Charges could be laid against the shopkeeper believed to have sold a knife to a seven-year-old boy, which he used to stab a teenage girl.
The boy couldn't be charged because of his age.
Detective Inspector Peter Fox has told 2GB’s Chris Smith, they're very concerned at how the boy got the knife.
“They shouldn’t able to purchase them,” he said.
“It appears on this occasion that he has come into possession of it and we’re conducting some investigation in relation to that.”