Fuelled by ice and cannabis, Lance Rhodes arrived at the Lalor Park home he shared with his mother, Linda Adams, and niece Hayley Rhodes, just before 11pm on September 8, 2015.
"We're going to have fun tonight," he said to Hayley, then 19.
The teenager said, "whatever" and went back to her bedroom, unaware of the horror that was about to follow.
About five minutes later, Hayley found Rhodes standing over her grandmother with a knife in his hand, saying "They're in the house ... don't worry I'll get rid of them."
As Hayley ran out of the house to get help, Rhodes continued threatening his mother. She too left the house and Rhodes chased her across the front yard of their Kennedy Parade home and into a neighbouring yard.
He stabbed her in the back and she collapsed. He then picked up a 28 kilogram concrete statue and bashed her, breaking her skull into multiple pieces.
Rhodes than walked back into the house and picked up a child by the neck and stabbed him in the chest.
He slammed the child's head against a wall then chased him out of the house and pulled him to the ground. Rhodes struck the child's face repeatedly with a piece of stone.
Both Ms Adams, 63, and the child, who cannot be identified for legal reasons, died of massive head injuries.
Rhodes went back into the house and said, "Die, just f---ing die, I don't care."
As neighbours called police Rhodes attempted to attack another woman, Annabelle Saludo, as she was getting into her car. With blood on his hands, he hit the car windows and yelled "F---ing open up", then attempted to open the car door. Screaming and swearing, he ran after the car and tried to lift it. As she drove away, he chased after her.
When Senior Constable Steve Lewis arrived, he told Rhodes to put down the knife. Rhodes picked up a water meter cover and walked towards Senior Constable Lewis, saying, "Let's go."
Senior Constable Lewis saw blood all over Rhodes' hands and body and, as the man refused to stop, the officer attempted to Taser him twice, but both times the stun-gun failed to fire.
Rhodes lunged at Senior Constable Lewis and the pair grappled on the ground. Other police officers arrived and Rhodes was subdued using capsicum spray and handcuffed.
In an interview at Blacktown police station, Rhodes said he had no recollection of committing the offences.
In the NSW Supreme Court on Friday, Rhodes, 36, pleaded guilty to murdering Ms Adams and the child, and to assaulting Ms Saludo and Senior Constable Lewis.
In a victim impact statement read of her behalf, Hayley Rhodes said: "I live with the memory of their screams and cries".
"My nan was the glue that held my family together," Ms Rhodes said.
"My whole life changed in just one night. Life as I knew it was over. My life was never what would be considered normal but I had my family and that was the most important thing."
Ms Adams' daughter Tina Rhodes said she was "ashamed" when she discovered her brother had killed their mother.
"It's like all the pieces of my family don't fit together any more," she said. "Mum was a beautiful soul. I miss my mum."
Crown prosecutor Terry Thorpe said that, while the murders were not premeditated, the victims were killed in a "sustained attack with a high degree of violence over a period of time".
"They were chased into the yard. There must have been a period when they were terrified and realised they were going to die."
An expert forensic pharmacologist found Rhodes had cannabis and methylamphetamine in his system.
Neighbours told police Rhodes was a known ice user and Rhodes made admissions to police during an interview.
The court heard that Rhodes might have an intellectual disability or mental illness.
"The Crown says there is some cognitive impairment, it may be inherent, it may be a result of attention deficit hyperactivity disorder or the result of the ingestion of drugs over a long period of time," Mr Thorpe said.
Ms Adams had taken out apprehended violence orders against her son over a period of years.
"He can't say the violence on this occasion was an aberration or out of character," Mr Thorpe said.
Rhodes' barrister Chris Bruce, SC, said his client did not have a history of serious violence.
"His behaviour on this night – in a drug-induced psychosis – was an uncharacteristic aberration," Mr Bruce said.
Justice Stephen Campbell will sentence Rhodes on June 2.