But those laws could still have allowed Mark James Bombara, 63, to have access to as many as five firearms as a recreational shooter and up to 10 if he was a farmer or gun club member.
Bombara killed Jennifer Petelczyc, 59, and her daughter, 18-year-old Gretl, at their Floreat home on Friday in an attack described as chilling and horrific.
He was reportedly searching for his wife when he went to the home and fatally shot them and then himself as police arrived at the property.
Bombara owned 11 guns under a recreational shooter's permit and two pistols under a collector's licence, one of which was used to kill Jennifer and Gretl.
Police Minister Paul Papalia said WA's proposed laws would be the toughest in the country; that they would have prevented Bombara from obtaining the collector's licence; and that he would have been limited to owning five weapons.
"This individual, sadly, was a fit and proper person, right up until the time he committed that act and he was a law-abiding firearms owner right up until he wasn't," he said on Monday.
"Under the current law that's what happens and that's why we want to make the laws tougher."
Bombara would also have been forced to undergo a health check with a mental health component.
The government will now consider further measures to strengthen the legislation, including giving police the power to seize weapons following family and domestic violence incidents.
Gun control expert Charles Watson said WA's proposed gun laws were extraordinary and advanced.
"In global terms, it'll be easily the best set of gun legislation in the world that's much better than the other states here - I think other states will be forced to look at what WA has done," Professor Watson told AAP.
Bombara was known to police because his ex-wife requested help moving out of their shared home in late March following a series of family and domestic violence-related incidents.
Premier Roger Cook said the chilling and sickening crime was motivated by domestic violence.
"Every Western Australian is still coming to terms with Friday's senseless act of violence," he said.
��SHE MATTERS: JENNIFER & GRETL PETELCZYC!��— Sherele Moody (Femicide Researcher) 🌈 (@ShereleMoody) For as long as men have been committing violence against women, women have been offering shelter, safety and support for women escaping that violence.And now we can't even support our mates, without being killed.Jennifer Petelczyc… pic.twitter.com/FvKfCZqB4HMay 25, 2024
The University of Western Australia said Gretl was a dedicated student undertaking a Bachelor of Science and a talented member of the UWA Water Polo Club.
"We are deeply shocked and saddened at the loss of such a young life," UWA Vice-Chancellor Amit Chakma told staff and students on Monday.
The water polo club paid tribute to the mother and daughter, who had been involved with it since Gretl joined a junior program in 2014.Â
"Jenny was a great supporter of the club and her daughter Gretl," the club said.
The sentiments were echoed by Gretl's former school, St Hilda's Anglican School For Girls.
"The Petelczyc family were well respected within the school community," principal Fiona Johnston said.
Tributes are flowing for shooting victims Jennifer Petelczyc and her daughter Gretl. (Aaron Bunch/AAP PHOTOS)
Police were called to the home in Perth's affluent western suburbs about 4.30pm on Friday after reports of gunshots, arriving as the last shot was fired.
Officers rushed the younger victim to Royal Perth Hospital but she could not be saved.
Lifeline 13 11 14
beyondblue 1300 22 4636
1800 RESPECT (1800 737 732)
4°C