Addendum: when I say Eastwood doesn't expand this particular world, the model I'm thinking of is Todd Field's In the Bedroom (2001) which is maybe the most riveting crime drama (so to speak) I've seen in years. Field's film goes well beyond the story of losing a child -- it's about the sheer painful impossible weight of that loss, and it almost goes to the point of shutting down the story to dwell on it in slow, agonizing, but not unbearable detail. It hits on a personal level in a way that Mystic River, for all its virtues, does not.