A quiet suburban street is the centre of a major police investigation after three members of a family were killed in “grisly scenes”.

Three members of one family have been killed in what police say was a “horrendous” scene in a southwestern Sydney home.

A man, understood to be a son of the family, has been arrested and is currently being questioned.

Emergency services found two people dead and a third critically injured after they were called to a house on Juliet Close in Rosemeadows about 1.30am on Sunday.

A fourth man was also injured.

Commander of Campbelltown City Police Area Command, Superintendent Grant Healey, said police were confronted with a “very grisly crime scene”.

“Blunt force trauma is always horrendous for people to confront, any weapon attack is always horrendous to confront,” he said.

“It’s a very extensive crime scene, so we haven’t recovered a weapon at the moment, but we’re systematically working through the granny flat out the back and then we’ll go through the house.”

Emergency services found two people dead in a house on Juliet Close in Rosemeadows Picture: NewsWire / Damian Shaw

A critically injured 64-year-old man died after being taken to Liverpool Hospital. Picture: NewsWire / Damian Shaw
Police believe the 32-year-old who was arrested about 2.30am after arriving at the home is the son of the man and woman aged in their 60s and the brother of the two men aged in their 20s and 30s.

Police are trying to track where he went after he allegedly fled the scene before returning a few hours later.

Superintendent Healey said “the surviving family member was the one that contacted police”.

He is believed to be a man aged in his 30s who was injured in the assault and taken to Liverpool Hospital but has since been released.

Superintendent Healey, said police were confronted with a “very grisly crime scene”. Picture: NewsWire / Damian Shaw

Three people dead in what police say was a “horrendous” scene in a southwestern Sydney home. Picture: NewsWire / Damian Shaw
Superintendent Healey said the family were not well known to police and have never interacted with police in relation to domestic violence.

He was not willing to give any information regarding what police believe happened in the home prior to the deaths.

“It’s very early in the investigation, so I can’t speculate,” he says.

He did confirm that all five people involved in the incident were living at the address.

Superintendent Healey was unwilling to confirm reports the attack was carried out using a hammer as investigators are yet to recover the weapon.

“Whilst we can say it’s a hammer, we’ve got to be 100 per cent sure. We’ll take our time and investigate it properly,” he says.

He did confirm that no firearms were used but said they believe multiple weapons may have been used based on the injuries.

“ … looking at some of the injuries, we suspect there may be more than one style of weapon,” he said.

“We think that there’s a bladed weapon involved, as well.”

Where to find help

If you or someone you know is experiencing sexual abuse or family violence contact:

National Sexual Assault, Domestic Violence Counselling Service 24-hour helpline 1800 RESPECT on 1800 737 732
24-hour Emergency Accommodation helpline on 1800 800 588
Safe At Home helpline on 1800 633 937
National Violence and Abuse Trauma Counselling and Recovery Service on 1800 FULLSTOP (1800 385 578). They also have a specific line for the LGBTIQA+ community called the Rainbow Sexual, Domestic and Family Violence Helpline on 1800 497 212
SHE (free and confidential counselling and support) on 6278 9090
Sexual Assault Support Services on 6231 1811, or after hours 6231 1817
Family Violence Crisis and Support Service on 1800 608 122
Bravehearts – Sexual Assault Support for Children on 1800 BRAVE 1
Kids Helpline is for young people aged 5 to 25 on 1800 551 800

Don’t go it alone. Please reach out for help by contacting Lifeline on 13 11 14

Men who have anger, relationship or parenting issues, should contact the Men’s Referral Service on 1300 766 491 or the Don’t Become That Man helpline on 1300 243 413

Police are trying to track the journey of the 32-year-old man who is assisting with their inquiries. Picture: NewsWire / Damian Shaw

Police are not willing to give information about happened in the home prior to the deaths. Picture: NewsWire / Damian Shaw
The 61-year-old woman was located first by police who took her into the yard and tried to administer first aid.

They then went back inside the house and found a 64-year-old man who was still alive but had serious head injuries.

A 37-year-old man was later found dead in a granny flat at the back of the property.

The critically injured 64-year-old man died after being taken to Liverpool Hospital.

The 32-year-old man arrested at the scene was taken to Campbelltown Police Station.

He is yet to be charged.