The police are his pawns, not the other way around. Shades of Silence of the Lambs . The good guys are a pair of detectives at opposite ends of their careers. His long years studying crime scenes and following up on clues have left him weary and jaded. In their quest to end this bloody, sadistic spree, the two cops appear well-paired, as together they make the perfect detective.
Mills is all brawn and little brain.
Somerset, on the other hand, spends long hours in the library researching Dante and Chaucer, looking for clues that will enable him to prevent the next killing. One of the problems with Seven is that Pitt's Mills is not an especially likable character. He's cocky and arrogant, with an inflated opinion of himself. Up until the end, he's convinced that his way is always the best. Pitt doesn't turn in one of his most impressive performances here, either.