Thousands gathered in the heart of Boorloo (Perth) on Wednesday to honour the life and mourn the death of Cassius Turvey, and to call for justice and change.

The protest is one of 44 held this week around Australia and around the world for the 15 year-old Yamatji-Noongar boy who was attacked on his way home from school on 13 October and died from his injuries ten days later.

At least 3,000 people were welcomed at Boorloo's Forrest Place to Country by Joe Collard, who thanked people around the world for their support.

Cassius' cousin Jasmine Rivers said his death had made parents afraid for the safety of their own children.

"Cassius did not deserve what has happened to him, nor do any of our children," she said.

"Australia as a country, we need to take a good look at ourselves and determine what the next steps are.

Crowd gathered at Boorloo's Forrest Place for the #JsuticeforCassius rally. Picture: Giovanni Torre.

"We should be able to live in a country knowing that when we send our children to school they will return home to use."

Ms Rivers spoke of Cassius as a much-loved cousin and uncle whose laughter reverberated through the house.

"My kids desperately miss their uncle," she said.

"Each and every day they say 'is Uncle Cassy feeling better, can we pick him up, can we bring him home?'

"We call upon our ancestors to give us strength and to show Australia today that we as a country need to change."

Long-time justice advocates Megan Krakouer and Marianne Mackay emceed the event.

Ms Krakouer said racism had been prevalent in Australia since colonisation.

"Hate fuels hate, violence fuels violence, and we can not be about that; we are better than that," she said.

"We need unity... to walk together to make sure future generations don't grow up with that colonialist mindset."

Ash Penfold led his traditional dance group in a performance to honour and celebrate Cassius' life.

"Your spirit, my little brother, lives forever," he said.

"Cassius we love you my man, today we dance for you.

"My heart breaks for the family... I have a little boy myself and my vision is for one day he came walk home from school with out fear and without being discriminated against."

Kiana Adams, a school friend of Cassius, said it was a privilege to have known him.

"He was such a well-mannered, respectful kid to everyone no matter who you were.

"Our community has lost a beautiful soul... Australia, we need to stand up. How can we let this keep happening?"

UWA Professor Pad Dudgeon acknowledged the "great strength" of Ms Turvey to back the national rallies in a push for change..

She noted the death of Elijah Doughty in Kalgoorlie in 2016 had seen the man who had hunted him down convicted only of dangerous driving and serving 19 months of his three-year sentence.

Ms Dudgeon said 517 Aboriginal and Torres Straight Islander had died in custody since the end of the Royal Commission into Aboriginal deaths in custody and not one conviction had arisen from any of those deaths.

Human rights activist Mervyn Eades said "black, white or brown, all children are sacred".

"We know we need to start coming together with love for us all," he said.

Human rights advocate Gerry Georgatos urged those present to nominate Mechelle Turvey for Australian of the Year for her fight for a better world.

There were several others speakers before a song and the Haka for life, after which the thousands gathered in Forrest Place marched through the heart of Perth, making the call for justice heard.