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

A Christchurch man convicted of repeatedly assaulting and then murdering his three-month-old daughter continues to deny responsibility for the earlier injuries and says the baby’s mother had more opportunity to inflict them.

Michael John Topp also says he did not get a fair trial and the whole process should have been aborted after a Crown expert witness gave “inappropriate” evidence that “tainted” the jury.

Topp was jailed for life with a minimum non-parole period of 17 years after he was found guilty of murdering his 3-month-old daughter in December 2022.

Michael John Topp on trial at the Christchurch High Court 01 May 2024 charged with the murder of his daughter POOL photograph by Chris Skelton credit: STUFF

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 his baby grievous bodily harm with intent.

The infant’s name has been permanently suppressed.

A jury found Topp guilty on all counts.

He appealed his convictions and sentence and his case was heard by the Court of Appeal today.

His lawyer, Phil Shamy, said there were two key issues.

The first was “damaging and dangerous” evidence given by a Crown witness about child abuse who had been “lauded as a world expert”.

“She had said people who killed are more than likely to be people who injure,” Shamy said.

“She said the literature tells her that… people who shake babies and kill them are likely to have done it before… done other injuries.

“I do not say that [she] did something or said something on purpose to somehow taint the trial… that… I’m just not of the view that [her evidence] was overly necessary. The evidence that was provided by the expert was so damaging and so dangerous.”

The matter was raised in court by Shamy, and Justice Ann Hinton gave a direction to the jury that the evidence was not admissible and they were not to rely on it in their deliberations. She also ordered the evidence be struck from the official record and did not appear in the daily transcript provided to jurors.

However, Shamy said the situation was “incurable” and the trial should have been aborted - which he requested at the time.

“The problems with this type of evidence is… that what you‘ve heard cannot be unheard,” he said.

“It was clearly very important evidence and I know… courts usually do have confidence, generally that directions will cure problems. But this court, in my submission, could not be satisfied that this man had a fair trial, given this type of evidence, having gone to the jury.

“In my view, this was simply incurable… and although the step is obviously a large one, this trial, given that it involved the murder of a child, needed to be aborted.”

Shamy said the appeal point was around who caused the injuries to the baby before the fatal assault.

“Mr Topp accepted that he had killed his daughter… the issue in terms of the other charges is whether he had committed them… one of the key matters was the issue of opportunity,” he said.

“They were both living in the house - Mr Topp and [the baby’s mother]. [Her] evidence indicates that Mr Topp spent a great deal of time working… long shift hours. Similarly, he spent a great deal of time going to the gym.

“So in my submission, the opportunity was there for [the mother] - probably more so than Mr Topp.”

Justice Anne Hinton. Photo / Michael Craig

At the trial, a friend of the mother recalled her worrying she may have injured the baby by shaking her.

The witness was “not happy” to be in court as she had been the mother’s “best friend” and her evidence had “caused that friendship to evaporate”, Shamy said.

As a result, she had difficulty communicating her evidence.

“The witness is being asked about how she would describe what [the mother] did, she is struggling to find the word… There was nothing in what she was saying that could be interpreted as jiggle, which is what Her Honour suggested,” said Shamy.

“I’m not saying that Her Honour in any way was entering the arena or behaving in a partisan way. I would not suggest anything other than Her Honour was trying to assist. The issue is, with the greatest of respect, she shouldn’t have.

“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 baby’s mother was “not being pointed to as a potential offender” despite having “opportunity”.

“Whatever she may have done… it was not suggested… that it was deliberate or that in any way she intended to harm her child,” he said.

“The way it was put is that there were a number of incidents where it could have occurred. She may have caused harm - unknowingly, unintentionally - and that was really part and parcel of this argument in terms of the other charges around opportunity because [she] spent the majority of time with the baby.”

Michael Topp was jailed for murdering his baby daughter. Photo / File

Senior Crown counsel Mark Lillicoe conceded with the Court of Appeal that the contentious part of the expert’s evidence was “inappropriate” and “gratuitous”.

“She shouldn’t have said it,” he said.

“She’s an experienced expert. She gives evidence routinely around the world… she’s an impressive witness, but this wasn’t impressive.”

He pointed out that the expert had “built in a caveat” by saying “often” people who killed children had injured them previously.

He said Justice Hinton’s direction to the jury was “more than capable” of remedying the situation.

“The direction was as clear as it could have been - the jury were not to use it. It was an explicit and easily followed direction - and they were also told the reasoning for it.

“It is easier to understand if you are given a cogent reason rather than just a direction.”

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

A second Crown lawyer maintained the trial was fair and that the intervention by the judge with the mother’s friend during her evidence “was in the interests of justice”.

“After two unsuccessful attempts to describe the movement, it was not inappropriate for the judge to intervene. In fact, it was necessary,” she said.

“It is the trial judge’s role to control the proceeding, which includes clarifying evidence for the jury. And in this case, it was necessary. The Crown’s position is that it was appropriate… that the single instance of judicial intervention complained of did not render the trial unfair.”

The Court of Appeal judges reserved their decision.

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 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.

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.

Justice Anne Hinton. Photo / Michael Craig

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 Anne 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”.

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