The man accused of murdering Rotorua baby Karlos Stephens was "putting on a show" in the hospital the morning he died, a nurse has told the court.
But the defence argues that everyone shows grief in different ways.
The observation was made by the duty nurse manager at Rotorua Hospital the morning baby Karlos was rushed in on November 30, 2014.
Shane Claude Roberts, 61, is standing trial for the murder of the baby some time between November 29 and 30, 2014.
The court had previously been told Baby Karlos died from "significant" head trauma that caused bleeding to the surface of his brain and behind his eyes.
The Crown argues Roberts assaulted the baby, causing the fatal injuries and was "reckless" as to whether he died or not, but Roberts' lawyer asked the jury to question whether it was "truly a case of murder" or if Roberts was even the person responsible.
The nurse, Joan Teddy, told the court this morning
that she had thought Roberts was "putting on a show" the morning Karlos had died because before he was told the news, he had been making "wailing" phone calls saying "Karlos is dead".
But she said he would quickly become "calm again" after hanging up.
She had asked the baby's mum, Pamela Stephens, a number of questions about what had happened but she had struggled to respond and it seemed like "she didn't know what to say", Teddy said.
Rotorua Hospital Emergency Department doctor Mazen Shasha was the first doctor to see baby Karlos that morning and remembered a nurse running over to him with a "floppy baby in her arms".
He was cold, motionless, and had froth coming out of his mouth, he told the court.
Shasha said the baby would have been "difficult to retrieve" at that time.
A team had worked hard to resuscitate the baby but did not have success, he said.
Rotorua Police Senior Sergeant Simon Betchetti was one of the first officers to go to the hospital the day of the death and told the court that the feeling in the room with Roberts and Stephens after the news was like nothing he had experienced before with grieving families.
He described the feeling as one of "resignation".
Courtney Scurr, the ex-partner of Roberts' daughter, had taken the stand first this morning and told the court that there were alcohol cans and baby vomit "everywhere" around the Homedale St address where baby Karlos allegedly stayed before he died.
She said the family went to the house the day of Karlos' death and it had taken "four hours" to clean the mess.
"Milky vomit" was throughout the hallway, on dining room chairs, and in the bath in the house, she said.
She recalled that she and her ex-partner Finesse Broughton had asked to adopt Karlos and his twin brother before his death but Roberts had said no.
She said they had thought the smartest option was for the babies to be in their care, to which Roberts' lawyer Simon Lance asked why she did not think to consult the biological mother about this.
She responded by saying that the biological mother, Pamela Stephens, had left the boys without a care to a man, referring to Roberts, who was not capable of looking after them.
After Karlos' death, she said Roberts had told them that he found Karlos on his stomach in bed "not breathing" and his mum Stephens had been "emotionless" at the morgue that day.