A suspected serial killer had racked up more than 100 criminal convictions before he allegedly murdered three First Nations women in Winnipeg, according to court documents and police.

Shawn Cameron Lamb, 52, has been charged with three counts of second-degree murder in the deaths of Lorna Blacksmith, 18, Carolyn Sinclair, 25, and Tanya Nepinak, 31.

Blacksmith鈥檚 body was found last week behind an abandoned house, wrapped in plastic. Sinclair鈥檚 body was discovered in March, inside a bag thrown in a dumpster.

Nepinak鈥檚 body has not been recovered, but police said they have enough evidence to indicate that she is dead.

Investigators said they are contacting police in other jurisdictions to see if Lamb has any links to unsolved crimes elsewhere.

Court documents show that Lamb has been in and out of jail most of his life. He was first charged with a crime in 1976 and his convictions range from forgery to theft to sexual assault.

Originally from Ontario, Lamb has done time in federal and provincial prisons across the country.  

According to court documents, Lamb has apologized for his crimes during previous court appearances and pledged to work on his 鈥渋ssues鈥� and drug addictions.

During a sentencing hearing in 2010, Lamb told the court he'd changed thanks in part to the teachings of aboriginal elders. He said he didn鈥檛 discover his aboriginal roots until later in life.

"I have a lot of life left to live and I'm going to live it and I'm not going to live it anymore in jail and I'm not going to live it hurting other people," he said at the time.

Aboriginal leaders are calling for a formal public inquiry into the fate of the more than 80 aboriginal women who have gone missing or been murdered in Manitoba over the last few decades.

The leaders and dozens of community members rallied at the steps of the Manitoba legislature in Winnipeg Tuesday evening, saying more needs to be done to solve cold cases and protect aboriginal women from predators.

But the Manitoba government said Tuesday it has no plans to hold an inquiry.

"We're not even discussing that at this time. They key thing is we don't want to get in the way of a criminal investigation," Justice Minister Andrew Swan said.

"Right now, that is our priority -- to try to get closure for the families that have been pained by this."

With a report from CTV鈥檚 Jill Macyshon and files from The Canadian Press