An Upper Hutt man has been sentenced to life imprisonment for murdering his baby stepson.
William Wakefield, 32, was found guilty by a jury of murdering 5-month-old Lincoln Wakefield, who died on 12 June last year after being shaken violently.
At sentencing at the High Court in Wellington, Justice Dobson said Wakefield would not be eligible for parole for at least 14 years and nine months.
He said there was an all-too frequent pattern of men abusing and killing children who weren't biologically theirs.
Justice Dobson said baby killings by non-biological fathers happened far too often and were a blight on the way we lived, and should not happen in a caring society.
He said the baby was vulnerable and helpless and the sentence should be a deterrent to prevent others displaying such dreadful behaviour.
He agreed with the Children's Commissioner that children are a gift and a treasure, who need adults to look after them and prioritise their interests.
However, he accepted Wakefield was remorseful and had earlier pleaded guilty to manslaughter which Justice Dobson considered as mitigating factors.
In Lincoln's mother's victim impact statement, she said she always pictures her son as smiling and giggling - and there will always be a cake on his birthdays.
She said she hopes Wakefield replays the moment he picked her son up and looked him in the eyes before violently shaking him, causing his death.
She had since found a strength she did not know existed, forcing her to make positive changes to piece her life back together.
She said her baby was now at peace because justice had been served.