A child abuse expert was quizzed by jurors today about why only one of the Kahui twins was seen to stop breathing around the time he believed that they sustained the brain injuries from which they later died.
It was the first question asked by the jurors at the trial in the High Court in Auckland of Chris Kahui, 23, who is charged with murdering his premature three-month-old twins Cru and Chris at the family home in Mangere in June 2006.
Starship Hospital paediatrician Patrick Kelly has said he believed the description given by witness Stuart King of Cru's apnoea episode suggested it was likely to have happened shortly after the baby received serious brain injuries.
While Dr Kelly was being cross-examined, jurors sent a question to Justice Geoffrey Venning asking why Chris junior did not show similar signs of apnoea to that of his brother.
Dr Kelly replied that he didn't know whether Chris junior was assaulted at the same time as his brother.
"If he was, I would have expected him to show similar symptoms," Dr Kelly said.
"Whether that would involve apnoea and fitting, I don't know. They sometimes do, they sometimes don't."
Dr Kelly subsequently admitted it was possible Cru's apnoea episode was not the first one he had that day.
"Is it possible what happened is a second episode? Yes, but what Stuart described was quite complex. That pattern of recovery from apnoea is quite common from a primary apnoea (occurring within minutes of receiving their injuries)," he said.
"It's such a typical account that it is most likely to be when the event occurred, but could Chris have walked in on similar complex event occurring later on? Yes it's possible."
When asked if it was likely to be the only time the babies stopped breathing, Dr Kelly said: "I think it's unlikely to be [the] only episode, and I can't say definitely that it was the first."
Timing is a key issue in the trial. Crown prosecutors say the timing suggests Kahui was the only person who could have injured the twins.
Kahui's lawyers say it is possible the babies were injured earlier in the day. They say someone else, probably the babies' mother, Macsyna King, killed them.
Dr Kelly also admitted his opinion on the reported good health of the Kahui twins earlier in the day depended on the evidence of Ms King and another witness, April Saunders, who fed the twins about noon on Monday June 12, telling the truth or not being mistaken.
"My opinion is completely dependent on the caregiver telling me the truth. That would apply to all the other witnesses."
Later, a detective said police did not tell prosecutors or the defence until early this year that a witness made significant statements to them last August about Ms King.
Detective Sergeant Chris Barry said his heavy workload and the wish to interview Ms King about the witness' statement meant he did not disclose the information until six weeks before the trial.
Defence lawyer Lorraine Smith said in opening statements at the start of the trial that the witness would give statements about admissions Ms King made to him.
Mr Barry said the witness, whose name was suppressed, gave a statement to police on August 24 last year but said he did not disclose the material until six weeks before the trial, which he admitted was later than ideal.
"What I did want to do was try and conclude the investigations around what (the witness) had told police and I felt it was important that in respect of what he told us that we needed to re-interview Macsyna King," he said.
However, a series of serious sex offence investigations towards the end of the year and a series of homicides in January in the Counties Manukau area put a pressure on time and he couldn't find the time to re-interview Ms King, Mr Barry said.
Mr Barry also talked about interviewing Ms King's sister, Emily King, about why mobile phone records suggested she was in Mangere at 7.54pm on the night the twins were injured, a time she said she wasn't there.
Macsyna King has said she was out of the area all night drinking with Emily King and a friend in another part of the city on the night the babies were injured. Mr Barry said Emily King could give no explanation for the phone site reading.
But he wasn't overly concerned because there was no indication that either Emily King or Macsyna King had returned to the Mangere house at that stage.
"All the witnesses we spoke to had said exactly the opposite."
Kahui's lawyers are expected to open their case tomorrow.
