WARNING: This story details of significant and fatal child abuse.

The Court of Appeal has rejected convicted Christchurch baby murderer Michael Topp’s claims that he was not responsible for a raft of serious injuries to his 3-month-old daughter in the lead-up to her final fatal beating.

Topp claimed that the infant’s mother had more opportunity to inflict them and told the Court of Appeal in May that he did not get a fair trial – in part because a Crown expert witness gave “inappropriate” evidence that “tainted” the jury.

His appeal has today been dismissed.

Michael John Topp. Photo / Pool

Topp was jailed for life with a minimum non-parole period of 17 years after he was found guilty of murdering his baby in December 2022.

He admitted causing the fatal injuries but denied the charge of murder, saying he did not intend to kill the baby.

He also denied three further counts of causing her grievous bodily harm with intent.

The infant’s name has been permanently suppressed.

Her mother’s name is also permanently suppressed. She has never been charged with harming her baby.

At Topp’s sentencing, Justice Anne Hinton shut down any claim that the mother was responsible.

“From all the evidence I heard and read during the trial ... You were an excellent and devoted mother,” she said.

“You could not have foreseen what Mr Topp was doing to [the baby] ... Even the doctors you took [her] to were totally unsuspecting ...

“It was in no way your fault. You are a victim.”

Justice Anne Hinton. Photo / Michael Craig

A jury earlier found Topp guilty on all counts.

He appealed his convictions and sentence, and his case was heard by the Court of Appeal in May.

His lawyer, Phil Shamy, submitted that an expert child abuse witness for the Crown had given “damaging and dangerous” evidence.

He said that as a result, the trial had been prejudiced and should have been aborted – which he requested at the time.

“This was a key piece of evidence, and if the Crown were having difficulty, then that was the Crown’s problem. There was no need here for judicial intervention,” he said.

The Crown maintained the evidence against Topp relating to the non-fatal assaults on the baby was “strong”.

The appeal was heard by Justices Jonathan Eaton, Sally Fitzgerald and Susan Thomas. Their reserved decision was released today.

“Mr Topp appeals his murder conviction on the grounds a Crown expert gave prejudicial, inadmissible evidence which was incapable of being cured by the judge’s direction,” said Justice Thomas in the decision.

Michael John Topp during his trial. Photo / Pool

“There were … three portions of [the] evidence which were problematic and, it is accepted, inadmissible.

“We are most concerned that this happened, particularly given the fact that there was a pre-trial decision which made plain the proper limits of that evidence. The inadmissible evidence disrupted the trial, with counsel and the judge diverted by having to deal with this matter.

“The appeal has created uncertainty for the victim’s family and unnecessarily consumed the valuable resources of the criminal justice system. The disclosure simply should not have been made. The court expects more from expert witnesses.

“However, in our view, the judge’s directions were entirely appropriate … the judge carefully explained to the jury why this aspect of [the expert] evidence was inadmissible.

“We are satisfied that the way in which this matter was dealt with by the judge sufficiently addressed the inadmissibility of this aspect of the evidence and cured any resulting prejudice to Mr Topp. It did not deprive Mr Topp of a fair trial.”

Shamy further submitted that Justice Hinton had crossed a line by “assisting” a Crown witness who was struggling while giving evidence.

Justice Thomas rejected the suggestion that had resulted in an unfair trial.

“A judge may ask a witness any question that, in the opinion of the judge, justice requires,” she said.

“Judges often intervene in order to clarify evidence so that it is understood by the jury.

Justice Susan Thomas. Photo / Pool

“We accept Mr Shamy’s submission that it would have been better had the judge not intervened. It was for the prosecutor to assist the witness … That said, we do not accept that the intervention created a risk of a miscarriage of justice.

“We are satisfied the judge’s intervention did not deprive Mr Topp of a fair trial.

“The appeal against conviction is dismissed.”

Topp’s violent, fatal offending

Topp’s daughter had been unwell during the night and her mother sat up with her. At 9am, Topp took over so the woman could sleep.

Both the infant’s and her mother’s names have been permanently suppressed.

At 12.25pm, he carried the baby into her mother saying she had been feeding and “seemed to start choking, coughing and gagging”.

She had been limp and gurgling for about 10 minutes.

The mother called 111 and paramedics arrived at 12.35pm.

The baby was rushed to Christchurch Hospital, where she was intubated and admitted to intensive care. Doctors ascertained she had an unsurvivable head injury as well as multiple fractures to her body.

She was later taken off life support and died within 10 minutes.

It was later revealed she was the victim of “repeated significant trauma and abuse” in her short life.

Along with the fractures, she sustained two severe head injuries before the final and fatal catastrophic blunt force trauma.

Topp's trial was held in the High Court at Christchurch. Photo / George Heard

Police said the injuries could only have been caused by Topp “yanking, pulling, smacking, sticking, squeezing, or applying pressure” to her tiny body parts.

Topp was charged with murder and three further counts of causing his baby grievous bodily harm with intent.

He admitted causing the injuries that killed his baby girl – but denies the charge of murder.

Rather, Topp said, the death was a case of manslaughter.

At sentencing, Justice Hinton accepted Topp’s offending was not premeditated, but it was significantly violent and reckless.

“You abused your position of trust – she should have been safe in your care. She was the opposite.”

Justice Hinton did not accept Topp’s claims of remorse, saying she did not consider him “genuine”.

How to get help:
If you're in danger now:
• Phone the police on 111 or ask neighbours or friends to ring for you.
• Run outside and head for where there are other people. Scream for help so your neighbours can hear you.
• Take the children with you. Don't stop to get anything else.
• If you are being abused, remember it's not your fault. Violence is never okay.
Where to go for help or more information:
• Women's Refuge: Crisis line - 0800 REFUGE or 0800 733 843 (available 24/7)
• Shine: Helpline - 0508 744 633 (available 24/7)
• It's Not Ok: Family violence information line - 0800 456 450
• Shakti: Specialist services for African, Asian and Middle Eastern women and children.
• Crisis line - 0800 742 584 (available 24/7)
• Ministry of Justice: For information on family violence
• Te Kupenga Whakaoti Mahi Patunga: National Network of Family Violence Services
• White Ribbon: Aiming to eliminate men's violence towards women.
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Anna Leask is a senior journalist who covers national crime and justice. She joined the Herald in 2008 and has worked as a journalist for 19 years with a particular focus on family and gender-based violence, child abuse, sexual violence, homicides, mental health and youth crime. She writes, hosts and produces the award-winning podcast A Moment In Crime, released monthly on nzherald.co.nz