Sheriff Bell is the character who represents the forces of good in this grim novel. Having experienced World War II, he betrayed his own fellow soldiers, and lives a life full of regret and shame as a result. He has therefore pledged to devote his life to the fight for justice and to helping others. However, as the text makes clear, the evil that he witnesses in the form of Chigurh, is an evil that he begins to suspect and finally realise is too much for him. Note what he says after visiting the cars of the original crime that were all shot up when he compares the kind of criminals he has to deal with now to the kind of criminals that his grandfather had to deal with:
Back then they was rustlin cattle. Now they're runnin dope. But I dont know as that's true no more. I'm like you. I aint sure we've seen these people before. Their kind. I dont know what to do about em even. If you killed em all they'd have to build a annex on to hell.
As the story progresses, Bell comes to realise that evil is a primal, elemental force that cannot be deterred by anybody's actions. If it wants to rise up and manifest itself, it will, and the powers of justice stand helpless in its wake. This is of course demonstrated by the death of Moss and his wife.