Mum Decapitated, Daughter Charged In 'Horrific' Domestic Violence Murder Investigation

A woman has been charged with the "horrific" murder of her mother after an alleged argument, with police opening a domestic violence murder investigation.

Jessica Camilleri, 25, faced court on Sunday afternoon after she allegedly attacked her mother Rita in their home in the western Sydney suburb of St Clair on Saturday night.

She did not apply for bail and told the court she had a number of health conditions, including border autism, bipolar disorder and anxiety.

The body of 57-year-old woman was found, suffering "multiple injuries" inside a home in the western Sydney suburb of St Clair, near Penrith, around 11.40pm on Saturday night, NSW Police said.

The woman was allegedly decapitated, with her head found several doors down from the home.

"This is up there with one of the most significant, most horrific scenes police have had to face," said Nepean Police Area Commander, Detective Superintendent Brett McFadden. First responders are receiving counselling after witnessing the scene.

"We understand at this stage that a number of knives were used during the course of the incident," McFadden said.

Her 25-year-old daughter was arrested in the front yard of the home. She has since been charged with murder, and will face court later on Sunday.

The scene at St Clair, where a 57-year-old woman was found dead and her daughter was charged. Photo: Kim Pratt/10 News First

A four-year-old boy at the home -- said to be the dead woman's grandson, but not the son of the 25-year-old -- suffered a minor head injury, and was taken to hospital for treatment. It is believed the boy witnessed the incident.

Officers had been called to the scene after reports of an argument between the women, which police said turned "violent".

Police said a knife was seized from the home for testing, with a number of crime scenes established inside and outside the residence. The incident is being investigated as a suspected domestic violence murder.

Strike Force Comeroy has already been established to probe the circumstances leading up to the woman's death.

McFadden would not comment on whether mental health may have been a concern in this incident, or whether the woman was under the influence of any substances.

Photo: Getty

"A canvass of the street has been conducted overnight, and interviews with witnesses are continuing," police said in a statement.

"Support is being provided for first responders."