It changes the complete view of the book, it's no longer in the perspective of a hyperactive child, it's now in the perspective of a reclusive adult who did his best to help children he cared for from afar.
It helped us see how someone as feared as someone like Boo sees the world. He didn't want to be feared, he wanted to be friends with Scott and Jem.
The crime control perspective
would be the justice perspective that this is referring to. This system
operates on a “for the greater good” belief, placing heavy sanctions upon the
criminal offenders and puts importance on the protection of the rest of
society.
