In this movie (unlike the sequels), Paul actually seems somewhat remorseful, where in the other ones, it seems like a mission. After his daughter is raped and wife murdered (by a young Jeff Goldblum), he takes to the streets, fighting back and showing that he's not going to put up with it anymore. The very last image of the film shows that Paul Kersey will probably not stop murdering muggers, he has just begun, hence the horrid sequels.......