Rusty talks Lip through how and why Barbara committed the murder while thoroughly cleaning the glass, destroying the only real evidence against him. They speculate whether Barbara left the glass at the scene because she wanted Rusty to know what she had done, or because she wanted him to be convicted. Rusty ultimately decides it doesn't matter, as he cannot bring himself to deprive his son of a mother and, except for Lip, will never admit the truth to anyone.
Rusty confides in Lip about how and why Barbara committed the murder while cleaning the glass, which destroys any evidence against him. They wonder if Barbara left the glass at the scene as a message or to ensure Rusty's conviction. In the end, Rusty decides it doesn't matter because he can't bear the thought of taking away his son's mother, and he'll never confess to anyone except Lip.