A Christchurch man has been found guilty of assaulting and murdering a 15-month-old baby boy at their Bryndwr home in 2015.
Troy Taylor was on trial in the High Court in Christchurch, accused of assaulting and murdering Ihaka Stokes.
The jury returned with a guilty verdict on both counts after four hours of deliberation today.
The 23-year-old was the partner of the boy's mother, Mikala Stokes.
Asked for his reaction to today's verdict outside court, Ihaka's biological father, Cameron Ellen, said "good job".
It was not in dispute that the baby died from head injuries that were not accidental.
But the defence suggested Ms Stokes was to blame for the boy's death - which Ms Stokes denied.
Following eight days of evidence, the jury of six women and six men retired to consider their verdicts about 11.30am.
A post-mortem examination found Ihaka had 59 injuries, including bruising to his head, swelling and haemorrhaging to his brain and fractures to both his shoulder blades.
During the trial, Crown prosecutor Mark Zarifeh alleged Taylor killed the 15-month-old on a Friday night in July after losing it due to the effects of the repeated concussion injuries he had suffered.
But, while giving evidence, Taylor told the court he loved and adored Ihaka, and the symptoms of the concussions only ever caused him to be frustrated with himself.
Taylor instead alleged Ms Stokes, who was alone in the house for three and a half hours on the day in question, was responsible.
He said he had lied to police in an earlier statement when he said Ihaka was fine when he returned home from getting a tattoo that night, and that he lied when he said a fall in his cot must have caused his death.
An ambulance was called for Ihaka about 11pm, about four hours after Mr Taylor got home. The child died at 11.40pm.
Taylor told the court that, when he went to check on Ihaka several hours after getting back to the house, he found him unconscious and floppy in his cot.
"I was not going to put Mikala in it. I knew that I had to make Ihaka out to be fine, to take it away from her."
But Mr Zarifeh said medical evidence presented to the jury unravelled Taylor's story.
A key Crown witness, neuropathology professor Colin Smith, told the court he did not believe there was medical evidence to suggest Ihaka had suffered the injuries earlier in the day.
If the injury had happened well before his death, the nerve fibres in Ihaka's brain would have been damaged, and that was not the case, Prof Smith said.
"In my opinion... both the naked eye and the microscopic pathology absolutely point towards this child going into cardiac arrest very close to the point at which the injury has been inflicted."
In his closing statement, Mr Zarifeh told the jury they could be sure, beyond a reasonable doubt, Taylor had assaulted and killed the baby boy.
But Taylor's defence lawyer, Phillip Shamy, told the jury that before they decided whether Taylor was responsible, it first had to be satisfied beyond a reasonable doubt that it was not Ms Stokes who inflicted the injuries.
Taylor was remanded in custody for sentencing until 9 June.