A family of four, including two school-aged children, have been found dead in a suspected double murder-suicide at a home in Perth’s affluent western suburbs.

Police found the bodies of a 50-year-old man, 49-year-old woman, boys aged 14 and 16, and three pets — two dogs and a cat — after being called to Mott Cl in Mosman Park about 8.15am on Friday.

“There’s two parents and two children so we will treat it as a double murder suicide,” detective inspector Jessica Securo said.

All bodies were found in different parts of a property on the short cul-de-sac, 15km southwest of the CBD, but it is not yet known how long they were there before the horrific discovery was made.

“What I can advise is that there was no weapon used during this incident and the family have no reported family violence matters with police,” detective inspector Jessica Securo said.

“We do know that both children experienced significant health challenges.”

The biggest clue for police, Securo said, was a note left at the home, although she did not elaborate on its contents or who wrote it.

“It will form part of our investigation,” she said.

‘Tragic incident’

Several streets remain blocked off although police say there is no ongoing risk to the community.

The alarm was raised by a person who received no response when they arrived at the home for a pre-arranged visit on Friday morning.

“A person known to the family attended the premises and became concerned and then subsequently contacted police,” Securo said.

“Police entered the house and located four persons deceased and three pets deceased.”

Securo confirmed the family had been working with care services and said the person who contacted authorities was “quite possibly” there to give medical assistance to the two boys.

“That will form part of our investigation as to what they were there to do,” she said.

Detectives are currently speaking with neighbours and looking for CCTV to piece together the family’s final hours.

“This tragic incident occurred only this morning and it will take time for police to investigate the full circumstances surrounding this,” Securo said.

“We urge members of the public to stay away from the area and be mindful that several streets in its vicinity are blocked.

“This is a highly distressing situation for all involved, from community members to the person that located the family to our first responders.”

St John WA sent several crews to the scene on Friday morning.

One local walking his dog said he was alerted to an incident when lights and sirens were “going off”.

“A lot of activity and some ambulances,” Darren Bolt said.

“Probably about five police cars there so there was quite a bit of action.”

Another returning from the beach said there was a “huge police presence”.

“Nice little quiet suburb. Not what we expect to see here,” Geoff Stewart said.

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