I can't comment on the subject of special needs, because I'm not well-informed enough to do so. But I do take issue with the idea that children only behave badly if they're grappling with inner trauma. There was a thread on here a while ago about a child who had done something very spiteful to a classmate, even though he was definitely old enough to know better. Some posters were actually calling the mother "malicious" for punishing him! Apparently she should just have talked to him and tried to understand why he did it, try to get him to empathise with the other boy, etc
Kids aren’t stupid – some of them will work out that if they say, “I did it because I was worried/upset about XYZ”, they can draw attention away from what they did wrong and get an easier ride (let’s be honest, all of us could name something in our lives that worries or upsets us). Same with asking them to empathise with the other person – some kids will realise that they can get away with picking on others as long as they say the right things if they get caught, even if they don’t actually mean it. That doesn’t mean these approaches are wrong – it’s just that sometimes, they will need to be accompanied by punishments if anything is going to change.
Yes, many children with behavioural problems are reacting to difficult home lives/being bullied themselves/feeling insecure, etc. but it’s not the case with all of them. To give an extreme example: I know someone who admits that he bullied a few kids at high school and feels awful about it now, as he never received any negative consequences for it. Many people would think that the way he targeted these kids – kicking and spitting at them when they walked past in the school corridor, spreading malicious rumours about them, making digs about their appearance in front of the whole class whenever a teacher left the room – must have been the result of some inner turmoil, but it really wasn’t. He was popular, he got good grades, he had a stable home life – he admits that he just got an ego boost from tormenting someone, making his classmates laugh, and getting away with it. It’s a myth that all bullies have low self-esteem.