On January 22 2010, Barnett's neighbour saw somebody run past her door. She thought it was unusual so went to Barnett's house. She noticed he had been drinking.
Barnett denied there was anyone else there, but the neighbour walked past Barnett and began looking through the house.
She opened the toilet door and found the girl holding an ice-cream and some lollies. The girl was crying and said she did not want to go home. The neighbour took the girl to her home and police were called.
When interviewed by police, Barnett said he befriended the girl while sitting in Murupara's town square. He told police he was lonely and was happy to chat to young people as he found them good company.
Barnett said he had not wanted the girl to come home with him but he found the girl at the door of his house. Barnett said he had not wanted the girl to come into his house but she pushed past him and went to his bedroom where the offending occurred.
Barnett told police he had given the girl money to go to the shop to buy an ice-cream and lollies.
"The fact that you were prepared to befriend and treat a young girl in this way has an element of grooming about it, particularly when it occurs around the point at which sexual activity has occurred," Justice Lang said.
Barnett had previously been sentenced to 12 months' jail after being convicted of having exploitative sexual connection with a vulnerable person - an 18-year-old girl with intellectual disabilities. Within a short time of being released from prison, Barnett had committed these offences.
Justice Lang said Barnett had not expressed any remorse and the only factor he could give Barnett credit for was his guilty pleas.
Barnett's offending had led to serious consequences for the victim, although the extent of that would not be known until she was older.
Justice Lang said a psychologist recommended that Barnett would need extensive counselling in prison if he was to have any hope of remaining trouble-free in the future.
Justice Lang ordered Barnett serve a minimum of four years and six months' jail before he was eligible to apply for parole.