Two children have described how a family station wagon hit speeds over 200kmh moments before it crashed off the road, killing four-year-old Konrad Truger.
His mother, Wendy-May Connon, was driving and appeared in the High Court at Wellington today where she pleaded not guilty to a charge of manslaughter.
Crown prosecutor Geraldine Kelly told the jury that on January 16, 2008, Connon drove from her home in Featherston, Wairarapa, with Konrad, two other children and two dogs.
While exiting a moderate bend at more than 140kmh Connon "lost it". The car left the road, flipping and rolling several times after a wheel clipped a culvert.
Konrad had been in the middle rear seat with only a lap belt and no booster seat, Ms Kelly said.
His body was found about 30 metres from the car and he died three days later of brain injuries
A blood test showed Connon had been smoking cannabis prior to the crash, Ms Kelly said.
Defence lawyer Jock Blathwayt said Connon had not been speeding and asked the jury to put aside their emotions when hearing about the death of a young boy.
"It would be normal to think 'someone has to pay for this'," he said.
The two surviving children - who are aged six and 12 but cannot be identified for legal reasons - gave evidence today and videos of their police interviews following the crash were played.
The older child told of trying to shift one of the dogs off the back seat so Konrad didn't have to sit in the middle but being scolded by Connon.
Konrad's booster seat was not in the car.
The child told the court once on the road Connon said, "I wonder if this car can do over 200kmh," then, "Oh we're doing it, we're doing it!"
Both children told the court they had seen the speedo showing over 200kmh before Connon began sawing at the steering wheel as the car weaved across the road.
"I was going to tell her to slow down but I was scared I would get told off," the older child said.
As they crashed she put her hand across Konrad in an effort to restrain him.
The younger child described seeing Konrad crash through the front windscreen.
Mr Blathwayt asked both children about conversations they had with adults following the crash.
He questioned whether they had been instructed to say the car was travelling at 200kmh.
The trial is expected to last two weeks.
