Personally I think they should try kids for a crime, if minor, they should recieve a sentence like an adult, but

It is pursponed till they are 18, if they stay out of trouble until they are 18, it will be quashed, but if they break the law again, they will be tried and given another sentence.

When they turn 18, they will do both sentences as an adult.

Now this would take a couple of years to take affect, but kids would then realise that it will be enforced and they will do time at 18 if they don't buckle down.

As said before, the main numpties will carry on, but it is the 1000's of hangers on that will seriously think twice before doing anything stupid.

In my eyes, the main numpty will be a waste to society, and so get them in the slammer, they will end up there anyway, but without their hangers on egging them on, they may be less inclined to act up.

Maybe I am way off here, but they are getting away with it until they are 18 anyway, atleast this way they would know that they have been punished and have the chance to rectify things