MONTREAL - Fredy Villanueva's parents led some 500 marchers Sunday to the site where one year earlier their 18-year-old son was shot and killed by police.

Almost to the hour of her son's death, a sobbing Lilian Villanueva knelt in front of the makeshift shrine in the Montreal park where he died and placed a white candle among the flowers and stuffed animals.

Since the shooting and widespread rioting that erupted in the low-income area a day after his death, the family has lived out their grief in public.

The past year has been difficult for the family, but there's hope something positive will come out of the tragedy, said Patricia Villanueva, Fredy's sister.

"If things change for the future, helped by the death of my brother, I think it would be a good thing for the family," she said, noting they helped organize two days of events in Montreal North commemorating Villanueva's death and aimed at increasing community involvement.

On Saturday, a series of workshops and a five-hour concert featuring local urban musicians took place without incident, as did the march that wound through the neighbourhood's streets Sunday.

A separate multi-faith vigil was also held at the shrine by a neighbourhood religious coalition earlier Sunday afternoon.

Despite the violence-free weekend, a rift remains between youth and police in the low-income area.

Police said they arrested four minors during the march who were found hiding on a school roof with "numerous" Molotov cocktails, pepper spray and metal bars.

Many of the demonstrators wore T-shirts emblazoned with stylized images of Villanueva's face and chanted anti-police slogans while families of other Montrealers killed by police spoke to the crowd about their loss and their anger.

Will Prosper, a local activist with the group Montreal-Nord Republik, says the Villanueva shooting has only increased tensions that were already present.

"People won't take injustice anymore," said Prosper. "Whenever there's injustice (police) know the population will rise up and do something against it. It will take lots and lots of work by the police they are going to have to admit that sometimes they make mistakes."

Fredy's mother also had harsh words for local law enforcement and called for truth and justice in her son's death.

"It's been one year since my son was killed by the damn police, " she said. "The death of my son shouldn't go unpunished."

Since the shooting, prosecutors have concluded that the police officers acted with justified force when they opened fire on the unarmed youths, killing Villanueva and wounding two others. They have not faced criminal charges.

In May, a coroner's inquest into the shooting was put on hold indefinitely when the presiding judge expressed concerns over the fairness of the hearings after several key witnesses said they would not participate.

Patricia says the family has not yet decided whether to take part in the inquiry.

"The government hasn't made this easy for us and we have to fight to get to the truth," she said.

"People have been shot and no one has been charged for this."