Police probing the riots that swept across Vancouver after the Stanley Cup final last June are serving media outlets with warrants to obtain more images of the mayhem.

Vancouver police announced Wednesday that The Vancouver Sun, The Province, the Globe and Mail, Global TV, CTV and CBC are being asked to hand over footage.

Insp. Les Yeo, commander of the integrated riot investigation team, said images from media outlets will add to the amount of evidence police have to hold rioters accountable for their actions.

"Anything that can give us the best evidence against these individuals is essential to us, and some of the best video footage we have is in the possession of the media," Yeo told reporters at a news conference Wednesday afternoon.

"The (investigators) are asking for raw footage, which includes stuff that was not broadcast."

The move on media outlets comes on the same day investigators announced that they're in the process of laying dozens of charges over the June 15 riots.

Police did not reveal what the charges were or how many people were involved. But Yeo said in a statement that investigators plan to deliver 40 charges to the Crown by Oct. 31, "and more charges will continue to flow in the weeks and months to follow."

Yeo told reporters later that dozens of people who had turned themselves in to police will be among those who will face charges by the end of October.

Yeo also said police are reviewing more than 1,600 hours of video captured during the riots, and are working with forensic analysts from across North America and the United Kingdom. Video footage, for example, has been sent to a forensic lab at the University of Indianapolis.

Yeo was forced again on Wednesday to respond to criticism that police have yet to lay charges in connection with the riots.

"As I said before, we're looking at charging up to 500 or 700 people," he said.

"This is probably one of the largest investigations of its kind in Canadian history and it does take a long time. This is not CSI where it takes an hour to have everything wrapped up."

Mayhem swept across downtown Vancouver last June when thousands of rioters fanned out into the streets after the Canucks lost Game 7 of the Stanley Cup finals to the Boston Bruins. Rioters caused millions of dollars in damage by torching cars, smashing storefronts and looting businesses.

Critics have accused police of being understaffed and underprepared for the fans who gathered in front of screens downtown to watch the game, many of whom were carrying alcohol.