A man who killed his father, the owner of a beloved greasy spoon in N.D.G., was sentenced to nine years in prison Friday.

John Koulakis pleaded guilty to manslaughter in the death of his father Tony, the owner of Cosmo restaurant.

Koulakis was found to be in a drug-induced psychosis when he killed his father in 2013. He was originally charged with second-degree murder, but the psychosis was a major factor in the prosecution's decision to downgrade the accusation to manslaughter.

The court heard that Koulakis consumed a massive amount of cocaine the day he killed his father, which triggered psychosis. Koulakis thought a Bruce Lee poster in his bedroom was urging him to kill “the devil” – actually his father.

Koulakis stabbed his father several times, while his father asked why he was doing it. His lawyer said they didn't go for a so-called insanity defence because of the accused's drug consumption.

“He consumed over $300 worth of crack the night in question just before the incident and he drank a bottle of wine. He put himself in that situation,” said defence lawyer Charles Montpetit.

The court subtracted the equivalent of four years for time already served, which leaves him with just five years left to serve. He could be eligible for parole after serving just under two years.

Koulakis is under psychiatric care while behind bars.