"You left Mr Gooch lying unconscious," Judge Francis Cooke said when Gray appeared for sentencing in the High Court at Whanganui on Thursday morning.
"He was left in the rain for about an hour."
Gooch was found by a member of the public in the early hours of April 20 and taken to Wellington Hospital.
He had hypothermia and a fractured skull and did not recover from his injuries, dying in Taranaki Hospital on May 9.
Before sentencing Gray, the Judge noted he had read a cultural report produced by Chester Borrows which identified Gray's struggles growing up.
"Your whānau background is characterised by abuse and neglect and social disadvantage," Judge Cooke said.
"Your mother had you when she was extremely young and you were removed from her care."
Gray went onto live in state and foster care, where he was both physically and sexually abused while also growing up in homes where alcohol was a big factor.
He was later reunited with his biological family who also suffer from cultural deprivation.
A pre-sentence report also identified that Gray had struggled with alcohol, depression and ADHD, none of which he has ever received treatment for.
Gray had 61 previous convictions resulting in 34 sentences of imprisonment, mostly for dishonest offending and with little history of violence.
Judge Cooke said Gray had identified his remorse for his actions and apologised to Gooch's family, some of whom were in the court.
He sentenced Gray to two years' and one month imprisonment.
