Cory Barry stabbed Justin Wendland twice in the chest at a Victoria bus stop in June 2010.
Surveillance video shows Barry fleeing the scene. He dumped the knife and then turned himself into police.
Barry had a history of mental health and addiction issues, but the Supreme Court judge rejected the defense's argument that he could not be held criminally responsible as a result.
The judge relied heavily on the expert psychiatrist report, which did not support the defense's argument that a brain injury or a mental disorder was to blame for Barry's actions.
The psychiatrist said he was baffled by Barry and his conflicting statements, and couldn't tell if he was lying or trying to dupe him.
Barry showed remorse during his confession, but after the verdict was read in court on Friday, he turned to the Wendland's mother with a smile and said: "I don't care, I'll be out in 10 years."
The victim's mother, Raj Wendland, wept as she spoke to reporters outside the court house.
"It's just really sad that he meant to kill Justin. What a kind, gentle person he was, always joking around and helping his sisters," she said.
A sentencing date has not yet been set.