A grandmother on trial for the manslaughter of her baby grandson lied to police on the night the boy died, a High Court heard.
Donna Parangi told police her daughter Lacey Te Whetu took Isaiah out of his car seat and inside the Rūātoki house for lunch before putting him to bed on November 2, 2015.
But the fact that Isaiah was left in the hot car for at least three hours was later admitted by Te Whetu and Isaiah's father Shane Neil, who have both been convicted of manslaughter for the 8-month-old boy's death.
The Crown says Parangi is culpable because she cared for Isaiah and his two older siblings and she also left the baby in the car that day after she and Te Whetu returned from a drug run to Kawerau, where they bought synthetic cannabis from a cousin.
The pair went inside, and with Neil they got stoned and fell asleep.
Yesterday the High Court jury at Hamilton heard that Parangi told a different story to police on the night and omitted details about buying drugs and getting stoned.
In reality, Isaiah was retrieved from the car at 3.30pm, hot and lifeless, according to Neil, and when the baby would not take a bottle, Te Whetu thought he was fast asleep.
She put him in his cot before returning to her slumber for three hours. At 6.30pm, when she couldn't rouse Isaiah, she dialled 111.
Paramedic Linda English said when she arrived Isaiah was warm, indicating to her his death was recent.
She and other paramedics attempted resuscitation for 26 minutes while Te Whetu wailed beside them in the ambulance.
In the minutes after her baby was pronounced dead, Te Whetu appeared to blame herself, Constable James Renwick told the court.
"F**ken rats*** man," Te Whetu said. "This is my baby. Our bubba's dead. Our bubba's sleeping. F**ken mum, didn't do her job, my boy."
Renwick read a transcript of a later police interview with Te Whetu, in which she clarified she was referring to herself as "mum".
When Renwick arrived at the scene that night, Te Whetu held Isaiah, wrapped in a blanket, while Neil slept.
"I saw her unwrap the baby," Renwick said. "There was a bruise on the left rib of the baby.
I saw her look at the bruise and let out a little sigh."
Renwick described the bruise as linear, about 10cm across the left rib.
The police officer said Neil was drowsy, incoherent and confused. Other witnesses said he was emotionless.
"He appeared to sleep at one point while we were talking. At one point he asked me what had happened to baby."
The court heard Neil had begun living at the house a month before Isaiah died, to help Te Whetu while she completed periodic detention.
Earlier in the trial, Parangi's defence counsel Susan Gray pointed to asphyxiation or abuse as the cause of Isaiah's death, not heatstroke.
The court also heard Isaiah had the flu and was unsettled the day before he died.