Whereas the beginning of the novel focuses largely on Jem and Scout's childhood and their obsession with Boo, the trial gradually begins to take over. For the first time, real racial tensions begin to emerge in the novel.
First-person point of view. If it was written in third person limited then you would only get the thoughts and feelings of only one character in the story,but if it was written in third person omniscient, then you would see the thoughts and feelings of another character. After that it goes to third person omniscient you may know things that other characters may not know yet.