Ponyboy changed due to the bleaching of his hair so was Johnny's but he died. He cut his, 'tough' hair. Also the bonds between Dally, Soda, and Ponyboy [Curtis brother] changed a lot due to the fact of running away.
Why did the neighbours immediately call the cops? Did they already know he was guilty? Were the cops making him go insane at the end? Did the cops suspect him before he admitted it? What is wrong with the narrator mentally? Is he even human?