Either bring back a system like the old Remand Homes, and/or make the parents of children under the age of criminal responsibility legally responsible for the actions of said child.
e.g. If a ten year old commits a felony, charge one of both of his parents with the crime as if they'd done it, which in way they have!
We have no sanctions we can apply to young children, corporal punishment is illegal, the law cannot touch them, and they know it, so they take advantage.
I have threatened to call the police to a couple of young thugs locally, and got the, 'They can't touch us' reply, time they were stopped from being able to maraud and damage with impunity.
Giok