Send him to jail, and he is likely to graduate with even less respect for the law, be subject to punitive conditions, and carry the stigma of a criminal conviction, all at a high public cost. One notes that affluent communities and public institutions already have stringent entry controls. I cannot get into Parliament, the BBC, the High Court, and well-off people's residences, without identifying myself and explaining my business. Working-class neighbourhoods should be allowed the same protection, given that they are the likely victims of violent crime and that the state has not succeeded in keeping crime at bay. Gates and other methods of shielding target areas have proven surprisingly effective.
Gates have another constructive effect.
They can help build community. Each of the six areas developed its own identity and social web. Children were heard to comment on the way to school that they must behave themselves because throwing stones or yelling aloud was not welcome in these parts. The undesirable effects of gated communities can be avoided by ensuring that neighbourhoods treat all who seek entry in the same manner. One still would prefer open communities, but gates seem necessary until crime, including terrorism, is better controlled.