Boolaroo stabbing: New details after a teenage girl allegedly murdered her younger sister in Lake Macquarie region

A teenager accused of killing her sister allegedly attacked her younger sibling “completely out of the blue,” police say.

The 17-year-old was arrested after her sister, 10, was found with stab wounds at Boolaroo, in NSW’s Lake Macquarie region, at 3.45pm on Monday.

The 10-year-old girl was treated by paramedics before dying at the scene.

Her older sister was then escorted by officers to Belmont Police Station and the murder charge was heard at Broadmeadow Children’s Court on Tuesday morning.

She was charged with murder (DV) and did not apply for bail. Neither she nor her family were present in court during the case.

Homicide Detective Chief Inspector Danny Doherty said police will allege the attack was random.

‘There is no evidence from the information we have at this time to indicate why this is [allegedly] happened,” he told reporters on Tuesday.

‘It’s very difficult to imagine. It is unthinkable that this could happen to a 10 year old.

“This is one of those incidents, as far as we know, that happened completely out of the blue.”

Police said the 10-year-old was allegedly stabbed multiple times in the upper body with a “sharp instrument.”

The girls were the only two children in the household and the family had not previously contacted police about domestic violence.

Detective Inspector Doherty said the family are still struggling to come to terms with the tragedy and offered his condolences.

“These are tragic circumstances,” he said. “There is a family that is still grieving and trying to come to terms with what happened.

“My thoughts go out to a mother who lost her 10-year-old child and now has another daughter before the judge who is allegedly responsible.”

The death of the ten-year-old girl has shocked the close-knit neighborhood.

Neighbors on the quiet suburban street were shocked Tuesday morning by the murder charges.

Residents were largely made up of retirees and young families, while others included people with special needs living in on-street facilities.

The house was located on a new development of detached, largely owner-occupied bungalow homes nestled in the hills.

The quiet estate is normally the scene of people walking their dogs and children playing, but it was still sealed off by police on Tuesday as forensic experts flocked to the scene.

A neighbor said she thought the house where the alleged murder took place was a rental because the yard was the only one not maintained.

“My daughter is the same age and she is afraid that someone will stab her too, so she is very shocked,” said another neighbor.

“You don’t think something like that would happen on your street.”

She described the street as quiet and said no one knew much about the family.

One woman trembled as she told Daily Mail Australia she thought no children lived in the property.

“There was an older woman living there and a younger one, maybe about thirty, but I didn’t see any children there.”

“The youngest was driving one of the cars and said ‘hello’ outside, but that was all.”

Ms Forsten said another neighbor had seen the girls at the property over Christmas but they had not been seen at the property since.

“I’m shaking,” she said. ‘It’s terrible.’

Another neighbor said: ‘The woman has lost everything.

“She’s lost her family, it’s a tragedy.”

Others who were home at the time of the alleged incident said they heard no noise from the home at all.

“We thought there were a lot of sirens in the area, but when they came onto the street they turned them off because there was no traffic.

“But then they knocked on our door and we found out it was on our street.”

The crime scene was still in place Tuesday morning as police continued to investigate.

Photos from the crime scene show shocked locals gathering outside the crime scene.

There were a number of police vehicles parked in the street on Monday evening as detectives left and left the home on Monday evening.

The latest incident follows a spate of unrelated stabbings in NSW in recent weeks.

It’s been two weeks since five women and shopping center security guards were killed in a stabbing at Westfield Bondi Junction on April 13.

Two days later, Assyrian Orthodox Bishop Mar Mari Emmanuel was stabbed in a church in Wakeley, Sydney’s west, on April 15.

A man, 28, was stabbed in Quakers Hill last Friday evening before dying on the way to hospital.