The kid has an argument with his father. The neighbors down the hall hear.
The kid goes directly to a junk shop and buys a switch knife for a friend.
The kid runs into his friends at a diner and shows them the knife.
The kid arrives back at home.
The kid goes to an all-night movie.
The old man hears, "I'm gonna kill you," and a body falling a second later.
The kid comes home to find himself arrested and his father dead.