Crown prosecutors at the trial of two men accused of murdering six people in a Surrey high-rise apartment seven years ago, say there is a powerful body of circumstantial evidence proving their guilt.

Matthew James Johnston and Cody Rae Haevischer are charged with six counts of first-degree murder in the so-called Surrey Six slayings.

In his closing arguments at the trial Crown counsel Mark Levitz said Johnston and Haevischer went to the apartment to kill Corey Lal because he failed to meet a deadline to repay a $100,000 drug debt.

Levitz said the pair also killed the other five people in the apartment so there would be no witnesses to Lal's murder.  The six had their heads covered when they were shot, the court heard.

He told the court the pair participated in the murders under the direction of Red Scorpions leadership, who were concerned leaving the debt unpaid would make the gang look weak.

Multiple homicide 20071020

An RCMP cruiser blocks the road leading to an apartment building in Surrey, B.C., on Oct. 20, 2007. Firefighters, who were first on the scene, initially thought they were responding to a deadly gas leak. When they arrived, they found the bodies of six men killed in a bloody massacre. (Richard Lam/Canadian Press)

Levitz also said video of the accused and a second person only identified as "Person X" taken before and after the murders further proves their guilt.

Last year former Red Scorpions gang leader Michael Le pleaded guilty to conspiracy to commit murder and was sentenced to 12 years in prison. Le's sentence was subsequently reduced to three years and one month after credit for time served. He then went on to testify against his former gang mates.

Two other men charged in the case, Jamie Kyle Bacon and Sophon Sek, will be tried separately at a later date.

6 victims found dead in highrise

In previous testimony court heard firefighters, who were first on the scene, initially thought they were responding to a deadly gas leak, but when they arrived, they found the bodies of six men dead in a 15th floor apartment suite in the 9800 block of East Whalley Ring Road.

A total of 19 shots were fired in the massacre, which took place around 2:40 p.m. PT on Oct. 19, 2007.The bodies were found in two groups of three inside the apartment.

The six all had their heads covered and shots were fired directly into the backs of the heads of three of the victims. One other was shot in the back, another in the head, and one in the face and neck.

Two of the victims — Christopher Mohan, 22, and Ed Schellenberg, 55 — were innocent bystanders who police say happened to be in the wrong place at the wrong time.

The other four victims, Ryan Bartolomeo,19, brothers Michael Lal, 26, and Cory Lal, 21, and Edward Narong, 22, were described by police as having criminal lifestyles.

At the time, Metro Vancouver was in the grips of a violent gang war dominated by a deadly rivalry between the Red Scorpions and the UN gangs.