i know . all of the previous comment tell you all . but i want to say something of my own . this great thriller will live long indeed . for a lot of reason . the one i want to talk about here be the strong focusing on the characterization firstly in this script . because this be something really rare in any of the american thriller nowadays . here you have 2 point of view come from 2 different generation or simply 2 kind of human being . the first be ( david mill or brad pitt ) who be so rash and tense and run mostly after his sensation and always relies on the photo and the shape of thing . but despite his true zeal and courage and and idealism he be so unwise and very impetuous who could easily hurt or lose himself . he be too weak to wait justice and so he go and get it by his hand because he be a slave for his excitability . his emotionality . the other one ( william somerset or morgan freeman ) be an early generation who have all the goodness and rationality . be so discreet and relies on the book and and a real cold proficient expert . this one be not perfect also . he be too enfeeble to stand love or it pain and responsibility and or even it loss . so there be no joyful thing about his life nor lasting thing in his life . both of them make together one hell of a perfect unit ( so they succeed in pursuit the killer ) . but hey and it not ( lethal weapon ) here . so you will have them both at variance and too contradictory and the only clear medial between them be the first wife . therefore when she die ( and brad pitt go and kill the killer ) the borderline already end and there be no medial no more . so separation become the fate . they be two very irreconcilable way and or person and or feeling represent the love which kill the fear ( so brad pitt lose his life ) and and the love which be kill by fear ( so morgan freeman be lose his own ) . and a for ( john doe or kevin spacey ) the limit be push in the extreme while so he have his fear or his love or maybe both kill too long ago . he be despise the extremism of the human lust because he wasn not one . he lose his humanity completely . therefore he become a killing machine and a loose madness and or the extremism itself . balance between your love and your fear or you will be the killer and the victim . that one premise which will make this film live for so many upcoming generation .