VANCOUVER - The British Columbia government hopes a public inquiry into the Robert Pickton case will answer the "lingering questions" that still persist nearly a decade after police first descended on the serial killer's farm.

The province's attorney general announced Thursday that hearings will examine how police handled reports of sex workers disappearing from Vancouver's poverty-stricken Downtown Eastside, many of whom ended up dead on Pickton's farm in nearby Port Coquitlam.

Pickton's arrest and subsequent year-long trial received intense international attention, but Attorney General Mike de Jong said there is much we still don't know.

"This is a situation in which upwards of 50 human beings went missing. We believe many, if not all, of those individuals were murdered," de Jong told reporters following a provincial cabinet meeting in Victoria.

"There are still lingering questions about the nature of these investigations, questions about whether more could have been done sooner, are we in a position to learn from the investigations and mistakes that may have been made."

The inquiry will have the power to compel testimony from witnesses and will make recommendations to prevent the horrific tragedy from repeating itself.

De Jong said he wants to know how dozens of women could disappear for years before authorities determined the disappearances could be the work of a single killer.

"How did this happen?" said de Jong.

"How is it that human beings, members of our society, whatever their socioeconomic circumstances, could go missing in the manner that they did without it seeing a full appreciation of the magnitude of what it seems was taking place until some years had passed?"

Pickton was arrested in 2002, setting off a massive search of his sprawling farm where investigators found the remains or DNA of 33 women. He was charged in the deaths of 27 women and eventually convicted of six counts of second-degree murder.

His convictions were upheld by the Supreme Court of Canada in July and prosecutors have said they don't intend to pursue any further criminal charges, including the 20 further murder charges he had been facing.

Lillian Beaudoin's sister Diane Rock was among the victims covered in those 20 charges.

"I just want justice," Beaudoin said in an interview Thursday. "And if justice means digging this far deep into it and finding out why the police made all the mistakes that they made and how this could have been prevented -- (that's) one of my main concerns."

Rock was one of the last to be murdered.

Victim's families have been calling for a public inquiry for years, demanding to know why police were so slow to catch a serial killer who was preying on their daughters, sisters and mothers.

That criticism has been directed at both the Vancouver police and the RCMP, but the two forces have taken starkly different approaches in response.

While the Vancouver force recently offered an unequivocal apology for its role in the investigation and released a report detailing everything it feels went wrong, the RCMP has yet to follow suit.

On Thursday, RCMP spokesman Insp. Tim Shields said if the force will respond to criticisms at the inquiry.

"If there have been allegations made that things could have been done better, then we as an organization say, 'OK, let's take a look, what could have been done better?"' Shields told reports.

"We agree that, with the benefit of hindsight now when we look back to 10, 12 years ago, sure, we might be able to find some things that should have been done better. ... There are many lessons that have been learned about what has been done right."

Shields said if the inquiry faults the RCMP for its role, the force will apologize.

He also repeated the RCMP's position that it disagrees with some of the findings of an internal Vancouver police review, which concluded both forces made mistakes that allowed Pickton to continue killing but placed much of the blame on the Mounties.

The Vancouver police report detailed a series of mis-steps, including a failure to effectively share information, a lack of leadership on both forces, scarce resources and a bias against sex workers among some Vancouver police staff.

The report said even after Vancouver police first forwarded information about Pickton to the RCMP in the late 1990s, 13 women disappeared from the Downtown Eastside, 11 of whom were later linked to Pickton's farm.

And it said the RCMP let the investigation go idle for months and then botched an interrogation of Pickton in January 2000 -- more than two years before his arrest.

Families and friends of women who disappeared from the Downtown Eastside started sounding the alarm in the early 1990s, but some have said when they reported those disappearances to police, they were told the women had likely moved elsewhere.

Kate Gibson, executive director of the Women's Education and Safe House in Vancouver, was ecstatic about the announced inquiry.

"I think it's just huge that they will be doing this. I think for all kinds of individuals, this is a very necessary next step."

She said she hopes the inquiry will be led by a woman, preferably an aboriginal, and someone who will be willing to take the hearings to the Downtown Eastside neighbourhood.

She said the inquiry will be most useful if it focuses not just on the women who have been killed and their families, but also on those who are living lives that make them vulnerable to predators like Pickton.