Chapter 6 : Why do you think Johnny decided they should turn themselves in?

After Dally informs the boys that Cherry Valance is willing to testify on theor behalf, they think about turning themselves in. Johnny is actually responsible for making the final decision, as he believes that possibly he'll be let off because he's never been in trouble. He also says that Ponyboy shouldn't be separated from his brothers for something that he didn't do.