I haven't read Les Miserables, but I don't think this is about "changing a criminal" since chances are the boy kept that lifestyle because obviously what brings him to robe has nothing to do with choice. But I find extremely amazing that the man (but well, he is a social worker, probably knows better about poverty in that city) thought on the boy and saw him as a person even when he was about to rob him. (Of course is not something I exhort people to do, but again, incredible.)