Hapuku, then 21, had been in charge of the infant in a sleepout at Ms Reti's parents' home in Kingsley Drive, Flaxmere, for much of the previous hour to 90 minutes, while Ms Reti was in the house feeding and bathing her elder son.
Evidence was given that for much of the time his focus was on clocking a PlayStation game.
At his sentencing, Mikara's mother Jamie Reti said she didn't know how anyone could hurt a baby like that and no parent should have to bury a child. Ms Reti had been pregnant with Hapuku's son when Mikara died. Their son was now nearly five.
It wasn't until a parole board hearing in 2014 that Hapuku acknowledged that he hit Mikara once in the abdomen leading to his death.
He confirmed it again at a parole hearing last August. At that time, his victim, Ms Reti said it was too soon for Hapuku to be released.
His sentence expires in September 2020.
The Reti family were concerned that Hapuku was now saying he was guilty so he could get an early release. The family maintain that they do not want Hapuku released to a Hawke's Bay address.
The parole report states that Hapuku is "generally well behaved" in prison although there were some earlier incidents of intimidation and having a negative attitude.
He had spent some time in segregation as he had concerns for his safety given the nature of his offending.
He was declined parole last August as he remained an undue risk to the community.
