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A teenage stepmother was allegedly at “breaking point” before she snapped and caused “catastrophic” stomp-type injuries that severely damaged a toddler’s organs and split her pancreas into two.

Experts will detail the extent of those injuries during a trial that started today in the High Court at Hamilton where Jessica Lee Rose Mulford is accused of murdering 2-year-old Harlee-Rose Niven on April 9, 2022.

Mulford, 20, is also defending an earlier charge of injuring with intent to injure the toddler while living in Tauranga on November 9, 2021.

In her opening to a jury of seven men and five women Crown solicitor Rebecca Mann said Mulford had a tendency to “snap” after building up resentment for having to look after a toddler that wasn’t hers.

Harlee-Rose’s father Dylan Berry was Mulford’s partner and the couple started to care for the little girl around August 2021 when she was a little over 18 months old.

By that stage, their relationship had become “more committed”, Mann said, and they were living together, initially with Berry’s parents in Tauranga before shifting to Mulford’s parents’ place in Pāpāmoa.

Mulford was just 17 at the time, while Berry was 19.

However, the couple “were not experienced parents”.

“Having Harlee-Rose come to live with them was an adjustment as you might expect... but it will become apparent that the biggest challenge was felt by Miss Mulford.”

With Berry having picked up work at a kiwifruit orchard, it was left to Mulford to look after Harlee-Rose, after dropping him at work for the day. She would then take her to Berry’s mother’s house, as it was closer to the orchard, before picking pick him up and returning to her parents’ house.

The first incident allegedly happened in November 2021 after Mulford dropped Berry at work and returned to his mother’s house.

Mann told the jury Berry will later give evidence saying Mulford called him at about 10.30am wanting her to drop Harlee-Rose off at the orchard so she could see her youth coach.

He agreed, but then he got another call soon afterward saying that Harlee-Rose had “fallen off the deck and her nose was bleeding”.

Harlee-Rose had blood on her face and bruising on her face and neck and was taken to a doctor who told her to take her to hospital.

When asked what happened, Mulford allegedly said the toddler had fallen off the deck onto the concrete below. She said Harlee-Rose was out of her sight at the time and moving her car and she turned to see her on the ground.

However, she also allegedly told others the injuries happened while at daycare - despite her never having been to daycare.

Mann said a doctor will give evidence that Harlee-Rose had a noticeable change in colour from her face and head - purple and black - compared to the rest of her body, scratches to the back of her neck and ear and “pinching” type injuries to her right ear.

She also had “dark marks” on her jaw and jawline, areas which Mann submitted, could not have been caused by a fall.

Afterward, Harlee-Rose remained in the couple’s care but Mulford’s mother was also there to supervise during the day.

‘She can f*** off’

Mann said tension began to grow between the couple around this time, with Mulford calling Berry names about how he had Harlee-Rose and “expressed some resentment that she was left looking after this child that was not hers”.

In text messages to her mother, Mulford made comments like “I can drop the f****** off”, and “she can f*** off where Dylan f**** off to”.

Mann said the couple stayed together but things started to get “fraught” in Mulford’s mind, as she would later send another text saying, “I just want Paige to have her back, I can’t do this anymore”.

Paige Niven is the little girl’s mother.

In early 2023 the couple decided to move in together - they had been living with their parents until now - but as there was nothing in Tauranga, they found a house in Hamilton. That meant Mulford was away from her support network, her mother and stepfather.

On April 3, 2022, six days before the toddler’s death, Mulford text Niven saying, “I am so over this f****** child. You chose to keep her and give birth to her and now I’m stuck looking after [her]... it’s so stressful looking after a kid that ain’t yours”.

Mulford then text to apologise for her language stating, “It’s getting annoying when I’m doing everything and don’t get a break”.

“It seems clear then that Miss Mulford was at breaking point,” Mann told the jury. “She had had enough.”

“She was so over this, and I quote, ‘f******’ child.”

‘April 9, 2022′

On the morning Harlee-Rose died, her dad was outside playing with a new kitten, keeping an eye on it and letting it get used to its surroundings. Mulford went inside to check on the toddler.

She told police Harlee-Rose didn’t want to go to the toilet because “she was sore”. So Mulford made her a bottle with a full ibuprofen pill crushed up inside. She put her down and checked on her 30 minutes later to find her “floppy and weird”.

Mulford ran and told Berry, who with help from a neighbour, drove Berry and Harlee-Rose towards Waikato Hospital.

However, upon spotting a patrol car on Heaphy Tce, they pulled over onto the footpath, with Berry desperate for help.

Medical staff would soon discover abdominal injuries so “catastrophic” that her pancreas had been split in two, lengthways, and all of her organs had been pushed back toward her spine.

Experts will testify the injuries were akin to being stomped on, Mann said, and she would have “decompensated” within minutes.

From then on, Mulford allegedly gave people, and investigators, varying versions of events as to what happened.

‘Miss Mulford is not responsbile’

Defence counsel Rebekah Webby said while her client admitted being with Harlee-Rose alone during the first incident, those injuries were caused by an accident.

As for the circumstances of the alleged murder, “Miss Mulford is not responsible”.

She asked the jury to consider “that there were two adults home that day, Miss Mulford and Mr Berry”.

“Miss Mulford did not and would not have ever inflicted the injuries on her.”

While the Crown relied on expert evidence, that “can’t tell you who caused the injuries and how the force was applied”.

“Miss Mulford doesn’t have anything to prove.

“The Crown could not, and will not, prove these charges against her.”

The Crown will call 29 witnesses during the trial, which is set down for two weeks and is being overseen by Justice Neil Campbell.

The public gallery is packed with supporters of both Mulford, Berry, and Niven.