"In Cold Blood" 3

"I was always thinking about Dad, hoping he could come take me away, and I remember, like a second ago, the time I saw him again. Standing in the schoolyard. It was like when the ball hits the bat really solid. Di Maggio. Only Dad wouldn't help me. He told me to be good and hugged me and went away. It was not long afterward my mother put me to stay in a Catholic orphanage. The one where the Black Widows were always at me. Hitting me. Because of wetting the bed. Which is one reason I have an aversion to nuns. And God. And religion. but later on I found there are people even more evil. Because after a couple of months, they tossed me out of the orphanage, and she put me some place worse." pg 128

I think this passage is important because it shows the human side of Perry, a small portion of all the charicterization Capote puts into Perry. Even though he is a killer, i guess its easier to sympathize knowing he's had a tough childhood - 3rd grade education, being abandoned, etc. It is also interesting why Capote devoted such a long chapter to describing Perry and his childhood, while mostly igoring Dick, the other killer. Knowing that the book is non-fiction, and that Capote had obsessively researched this story, it may be that he just liked the guy more and wanted to put more of what led Perry to do the things he did into the book, instead of it having any particular importance to the book in comparison to the other characters.

Questions:
Why so much perry charicterization? still no idea on the killing motivation...
Why do they go to mexico, then come back?