Steve was one of the victims of a vengeful ghost.
Steve was mopping the floor of a college science room when blood started dripping. He noticed that it was coming from a large cut on his forehead. This confused Steve, since he didn't know where he got the cut from.
He was soon confronted and attacked by a moving anatomy dummy. His corpse was later found lying on the floor with a blade in his throat.
While Johnny tries to explain what happened in the past to Sam Winchester, Steve is shown in a flashback with his friends, including Johnny. The group had pulled a prank on Rose Brown, convincing her that she had a secret admirer.
When Rose tried to walk away, Steve grabbed her wrist, telling her to "take the joke", but when Rose pulled she fell onto a table, and bashed her head on the edge. She died instantly.
Steve convinced Johnny not to call the cops, something Johnny fully regrets.