Chapter 11 of The Outsiders begins with Ponyboy confined to bed rest in order to further facilitate his recovery. He spends some time looking through a yearbook before he is told that he has a visitor. The visitor is the Soc Randy. Randy was Bob's best friend.
Randy said a couple of important things to Ponyboy. The first was that Randy's father knew about everything and wants Randy to tell the truth in court.
"My dad says for me to tell the truth and nobody can get hurt. He's kind of upset about all this. I mean, my dad's a good guy and everything, better than most, and I kind of let him down, being mixed up in all this."
Randy then asks Ponyboy what Pony's father thinks of the entire situation. Ponyboy explains that both of his parents are dead, and it surprises Ponyboy when Randy expresses sympathy.
Randy also tells Ponyboy that it was Johnny who killed Bob. Ponyboy denies this information and claims it was him (Ponyboy) who killed Bob. It is Pony's attempt to further protect Johnny. All of the Greasers cared for Johnny, and all of them likely would have made the same claim.
I was bewildered. "I killed him. I had a switchblade and I was scared they were going to beat me up."