Alfred Walcott (clockwise from top left), Brianna Helen Kinnear, Nicholas Smith and Jeff Cornell were all shot dead. Police sources have told CBC they were street-level drug dealers known as 'crews.' (CBC)

The deaths of four people who were gunned down in the last year in Metro Vancouver are being investigated for links to a drug-dealing group.

Police are looking into possible connections in the deaths of Alfred Walcott, Jeff Cornell, Brianna Helen Kinnear and Nicholas Smith, said Cpl. Dale Carr of the RCMP's Integrated Homicide Investigation Team.

Other police sources told CBC News the four shooting victims were associates of Troy Dax McKinnon and Jesse John Margison — and were all street-level drug dealers known as "crews," who do not belong to full-fledged gangs in Metro Vancouver but often work with or for them.

"Mostly if they [the crews] lose the drugs and or don't pay back the money that they owe, that can get them into a whole heap of trouble," Carr said Tuesday.

The trail of death of the four members began over a year ago when Walcott, 22, was shot dead in Coquitlam in March 2008. Two days later, Cornell, 31, was found shot dead along a roadside in Maple Ridge-Pitt Meadows.

RCMP Cpl. Dale Carr of the Integrated Homicide Investigation Team says investigators are trying to connect the dots in the four deaths. (CBC)

On Feb. 3 of this year, Margison's girlfriend, Kinnear, 21, was found shot dead and slumped over the steering wheel of a vehicle in Coquitlam. Eight days later, Smith, 22, was gunned down in a basement suite in Vancouver's east side.

Police allege McKinnon and Margison were involved in a December 2006 incident wherein a quantity of drugs and cash went missing, ending in the July 2007 forcible confinement and mutilation of a North Vancouver man.

Margison was arrested and charged last month, but McKinnon is still at large.

The Integrated Homicide Investigation Team is still trying to determine exactly why the members of the drug group were methodically targeted, said Carr, who would not reveal further details of the police investigation.

Walcott, the first of the four members gunned down, had told a family member the night before he was shot dead that he was in trouble, police sources told CBC News. He said he had made money for somebody and that they wanted it — but that he didn't have it anymore.

Carr said Tuesday that the slaying of Walcott, Cornell, Kinnear and Smith should serve as a warning to others involved with gangs and the illegal drug trade.

"They run the risk of having bosses that don't like the end result and end up using violence as a way to settle the score," Carr said.

With files from Eric Rankin