Maureen Horstman (67) and daughter Tamara (26), a former dux at Prendiville Catholic College, were found dead by Tamara’s twin brother, Nicholas, at their Felgate Place home on Sunday, December 29.
Mirrabooka man Lesley Jonathon Cameron (19) was charged with their murders last Wednesday.
He was also charged with aggravated burglary and vehicle theft, having allegedly fled from the scene in a Mazda3 stolen from the home.
Flowers and two crosses were laid outside the property as neighbours gathered on Wednesday night to express their shock and grief over the violent incident.
A forensic team remained at the home all of last week as local officers kept guard.
Mr Cameron appeared in court on January 1. He was not required to plea and did not apply for bail.
He was remanded in custody to appear in Stirling Gardens Magistrates Court on January 29.
The deaths ended a concerning month for north west district police who had already faced two violent deaths at the beginning of December.
On December 5, Koondoola resident Sally Kaur (57) was murdered after she was allegedly stabbed by her 19-year-old stepson.
Just two days later, a 34-year-old man was alleged to have seriously assaulted 31-year-old Damien Ruppell in Clarkson.
Mr Ruppell later died in hospital.