Quote 1
[The grandmother:] "Here this fellow that calls himself The Misfit is aloose from the Federal Pen and headed toward Florida and you read here what it says he did to these people. Just you read it. I wouldn't take my children in any direction with a criminal like that aloose in it. I couldn't answer to my conscience if I did." (1)
We get a lot in this seemingly ridiculous warning from the grandmother. First, it makes introduces The Misfit right at the beginning of the story, and gives the reader the feeling that a confrontation with him is inevitable. It also sets up the story's great irony: the grandmother will be the one who brings everyone to The Misfit, by taking them down the wrong road, by indirectly causing the accident, and then by telling The Misfit that she recognizes him. Even if the encounter with The Misfit is unintended, should the grandmother to be faulted for this, especially in the moment when she reveals she knows who he is? That she even brings up "conscience" here is also suggestive. The grandmother is implicitly setting herself up as a "good" person, since good people are people who follow their conscience.
Quote 2
"You must have stolen something," [the grandmother] said.
The Misfit sneered slightly. "Nobody had nothing I wanted," he said. "It was a head-doctor at the penitentiary said what I had done was kill my daddy but I known that for a lie." (116-117)
The grandmother, still trying to convince The Misfit that he's a good man, assumes that the crime he committed must have been the most "respectable" kind, (i.e., stealing). She knows better; it was she who brought our attention to The Misfit's being dangerous (presumably a killer) at the beginning of the story. The Misfit's response is revealing. He claims that he's not interested in crime because he wants to get rich or take things from others. What, then, could be his motivation? Nothing, but the pleasure of destroying things, out of "meanness."
Quote 3
[The grandmother] saw the man's face twisted close to her own as if he were going to cry and she murmured, "Why you're one of my babies. You're one of my own children!" She reached out and touched him on the shoulder. The Misfit sprang back as if a snake had bitten him and shot her three times through the chest. (136)
The grandmother's "moment of grace" and The Misfit's response. We've got a lot to say about this elsewhere (check out "What's Up with the Ending") because it's the central moment of the story. Is this an actual transformation in the grandmother, a product of delusion, or a last attempt at manipulation? How you see it will also influence how you see The Misfit's reaction. Any reading, though, has to make sense of the violence of the reaction. It's as if at this moment he's encountered something very threatening, completely alien to himself, as in the "snake bite" image. What's either revealing or ironic about that image is that the snake to which the grandmother is compared is a creature often associated with evil or with being an "enemy of man" (as it is in the Bible story of Adam and Eve). Perhaps that's the way genuine good appears to genuine evil.