108). Clue: Dick feels Perry is mentally unbalance, but fails to see his own behavior as anything but "normal," when it is far from it

Precognition that Perry is tainted

They shared a doom against which virtual was no defense (p. 185).

Clue: Perry's sister Barbara sees Perry also as damaged goods.

Rivalry and one-upmanship going out of hand.

[Dick] was holding the knife. I asked him for it, and he gave it to me, and I said, 'All right, Dick. Here goes.' But I didn't mean it. I meant to call his bluff, make him argue me out of it, make him admit he was a phony and a coward. See, it was something between me and Dick. I knelt down beside Mr. Clutter, and the pain of kneeling -- I thought of that goddam dollar. Silver dollar. The shame. Disgust....

And they'd told me never to come back to Kansas. But I didn't realize what I'd done till I heard the sound. Like somebody drowning. Screaming under water (p.244).
Clue: Dick promises to blast hair all over the wall, but Perry doesn't think it will happen -- both are being so macho they let things get out of control.

Disassociation and psychosis

I didn't want to harm the man. I thought he was a very nice gentleman. Soft-spoken. I thought so right up to the moment I cut his throat (p. 244).

Clue: What sane person can, in the same sentence, talk about loving the attributes of their victim and then slitting their throat?

Psychological accident, but a preventable one

The crime was a psychological accident, virtually an impersonal act;