A Christchurch teenager who left a man for dead while high on synthetic cannabis... has been sentenced today

65-year-old Pierclaudio Raviola was found unconscious at a Sumner beach car park in March last year - later dying in hospital.

18-year-old Moses Eli Hurrell was sentenced to three and a half years on charges of manslaughter and burglary in the Christchurch High Court .

The court heard Hurrell had begun using synthetic cannabis at an early age - with Justice Nick Davidson calling it a scourge on society.

Justice Davidson says Hurrell needs help with rehabilitation for his drug and alcohol problems... and lip service isn't enough.