A paediatrician said today Chris Kahui may not have known his twin sons were fatally injured because he was not the babies' main caregiver.
Chris Kahui is on trial for murdering the three-month-old boys Chris and Cru. They died on June 18 2006, within about 14 hours of each other at Auckland Starship Hospital.
Kahui has shown little emotion throughout much of his trial, which began on Monday but today wiped tears away from his eyes as Dr Lindsay Mildenhall spoke about the rib fractures the twins had.
The Crown alleges Kahui caused the fatal injuries on June 12, 2006 after he crumbled under the pressure of looking after three young children and visiting his ill mother who was in hospital.
Dr Mildenhall, a paediatrician at the neo-natal unit where the prematurely born twins stayed for a month before being allowed to go home, said they were healthy and robust when they left hospital.
The twins' parents only visited 11 times during the 30 days, often fleetingly, with neither Kahui or Macsyna King feeding the babies or changing nappies, he said.
Staff were concerned about the lack of attendance, particularly Ms King's absence, he said.
Dr Mildenhall, who worked on the twins when they were admitted to hospital in June, said the injuries the twins received when they were brought in were similar to a difficult and sometimes disastrous birth.
The injuries were such the babies would not have been able to feed normally.
Under cross-examination, Dr Mildenhall said it was possible a layperson, and particularly someone who was not the main caregiver, would find it difficult to detect any abnormalities.
This afternoon Stuart King, brother of Macsyna and partner of Kahui's sister Mona, told the court his sister was the dominant person in the relationship, while Kahui was placid and easy going.
"She (Macsyna) can moan and swear like no one's business. She'll just go and go and go."
Ms King would not back down and would "go in guns blazing and really let you have it".
Kahui could "take whatever crap" but would "bottle things up and then blow up."
The trial continues.
