Police have begun a double murder-suicide investigation after a man shot two women before turning the gun on himself at a home in Perth's west.
Police believe the 63-year-old was searching for his ex-partner before he shot a gun that killed two women and himself at a home on Berkeley Crescent in Floreat around 4.30pm (6.30pm AEST) yesterday.
Police said that the 59-year-old woman was a friend of the man's ex-partner.
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Officers confirmed the former partner was not at the home but the two women, including the 18-year-old daughter of the 59-year-old, were "tragically" killed.
Police are investigating if one of the women was cable-tied during the incident.
The man was known to police however he had no known history of violence.
He was a licensed firearm holder in WA, police said today.
9News understands the man's ex-wife had sought refuge at her friend's Floreat home.
Police confirmed today that she is is helping them with the investigation.
"These are distressing circumstances," Detective Inspector David Gorton said.
"Any death is tragic, when you have a multiple murder it has that greater impact on the family, the friends, the first responders, and certainly the community at large," he said.
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"We're not treating this as a family violence matter."
This morning police confirmed that the 18-year-old lost her life in hospital after she was transported there in a critical condition yesterday afternoon.
Perth Mayor Basil Zempilas shared a message on social media to the community about the "heartbreaking and unimaginable" tragedy before revealing he has a connection to the deceased.
"This is a shocking event which has left the local community stunned and in mourning," he began.
"Like many in the area, as is so typical of our area, my family had a connection to the mother and daughter who so terribly lost their lives.
"To their family, friends and neighbours, please know the Floreat community is grieving with you and is here for you."
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Police said a large amount of police resources were deployed to the area yesterday, including the Tactical Response Group and specialist detectives.
An investigation into their deaths is ongoing.
"WA Police will continue to provide support and assistance to the family, friends and first- responders affected by this tragic incident."
Support is available from the National Sexual Assault, Domestic Family Violence Counselling Service at 1800RESPECT (1800 737 732).
If you or someone you know needs help or support, Lifeline can be called on 13 11 14 or at www.lifeline.org.au.