A teen dad who was meant to be caring for his 5-week-old son so his partner could sleep smoked cannabis several times throughout the night - a move the crown say contributed to the baby’s death after he was struck in the head while being burped and dropped to the floor twice.

Rawiri Sergeant, of Ruakākā, is on trial in the High Court at Whangārei for manslaughter over the death of his baby, O’Shea Tuhoe Sergeant.

On the night of November 18, 2021, O’Shea’s mother, Jazmyne Thacker was so exhausted the couple agreed Sergeant - who was 18 years old at the time - would take over the night feed to allow Thacker to get some much-needed rest.

The couple lived in Sergeant’s mother’s home in Ruakākā. She was away on holiday with her partner and two children.

Thacker expressed enough milk for Sergeant to feed O’Shea through the night and went to sleep in their bedroom while Sergeant set himself and O’Shea up in the spare room.

The court heard how Sergeant gave O’Shea his first feed about 9pm, left the baby inside went outside to his car and smoked a bong of cannabis. He returned to settle the baby, who woke again between 11pm and 11.45pm for his second feed.

Again, Sergeant fed O’Shea and settled him again before going back outside to smoke a second bong in his car.

About 4am, O’Shea woke for another feed, this time the Crown said Sergeant went to his car before feeding the baby and smoked a third bong of cannabis.

Each time he went out he smoked approximately 1 gram of cannabis.

After he came back inside and fed O’Shea he placed the baby on his knee to burp, holding him around the chin and patting his back.

Baby O'Shea died in November 2021 after emergency services were called to an address in Ruakākā. Photo / NZME

The Crown said the baby’s head jerked backwards and then forwards, and as he fell forward, Sergeant’s knee connected with the left side of O’Shea’s head.

The Crown said the baby rolled off his knee but Sergeant managed to catch him.

About 9am, Sergeant picked up the baby and when he went to put him down with his mother so he could search for his cannabis, O’Shea started crying so he picked him up again.

Sergeant prepared a bottle and spent 10 minutes looking for the lid to his cannabis grinder before attempting to feed O’Shea.

This time, the court heard O’Shea did not latch on to the bottle and Sergeant noticed his limbs were floppy and he was not responding.

Holding O’Shea at chest height, Sergeant allegedly dropped the baby on the floor. When he checked whether the baby had a heartbeat he noticed blood coming from O’Shea’s nose and began CPR.

The court heard he then picked the baby up, ran to the bathroom to splash his face with water and wipe his nose. When he returned to the lounge, he allegedly dropped the baby again from chest height.

Emergency services were called but O’Shea was pronounced dead at 9.47 am on November 19, 2021.

In Crown openings before a jury of five men and seven women, prosecutor Geraldine Kelly said O’Shea’s death was the result of a subdural haematoma due to head injuries.

“The actions of consuming cannabis while being responsible and then failing to protect him from a fall and drops were a major departure of the standard of care a reasonable person should have given to O’Shea,” Kelly told the jury.

“Because of his decision to consume cannabis, and failing to protect him from injury is why he is now before you on the manslaughter of O’Shea.”

Sergeant’s lawyer Arthur Fairley said the jury needed to look at the building blocks of the charge and the two points of incident in whether his client departed from care.

“What the defence say is, sure he consumed cannabis. He was holding the baby. Baby rears back, drops and instantly hits the head but he stops the baby from falling to the floor. You have to be sure it’s a major departure from care.

“The 9am incident, there was no cannabis. Sure he might have dropped baby, but he realised something was seriously amiss and he’s panicking, it’s nothing to do with cannabis,” Fairley said in openings to the jury.

Twenty-five witnesses will give evidence including doctors, plunket nurses, midwives and the baby’s mother.

The trial is scheduled for three weeks before Justice Christine Gordon.

Shannon Pitman is a Whangārei based reporter for Open Justice covering courts in the Te Tai Tokerau region. She is of Ngāpuhi/ Ngāti Pūkenga descent and has worked in digital media for the past five years. She joined NZME in 2023.