Convicted killer maintains Leslie Greenwood was first to shoot couple

Leslie Greenwood is accused of first-degree murder in the deaths of Barry Kirk Mersereau and his wife, Nancy Paula Christensen, who were shot at their Centre Burlington, N.S., home in September 2000.

Greenwood on trial for 1st-degree murder in September 2000 deaths of Barry Mersereau and Nancy Christensen

Leslie Greenwood is escorted through the courthouse in Kentville, N.S., earlier this week. (CBC)

A convicted killer testified Friday he shot a Nova Scotia couple at their rural home in September 2000 to pay off a drug debt, but maintained he was only an accomplice to the man he says was the first to pull the trigger: Leslie Greenwood.

Greenwood, 48, is on trial in Nova Scotia Supreme Court in Kentville for two counts of first-degree murder in the deaths of Barry Kirk Mersereau and his wife, Nancy Paula Christensen, at their home in Centre Burlington.

It is the second time Greenwood has gone on trial for the charges. He has pleaded not guilty.

The Crown's star witness in the case is Michael Lawrence, who is serving a life sentence after pleading guilty to first-degree murder in the deaths of Mersereau and Christensen. He also confessed to killing Charlie Maddison the day before in order to use his pickup truck as a getaway vehicle.

Michael Lawrence is seen during a court appearance in 2012.

Lawrence began his testimony Thursday and faced cross-examination Friday.

Lawrence has said he agreed to take part in the murders of Mersereau and Christensen in order to pay off a $28,000 drug debt to a man named Curtis Lynds, who wanted the couple dead. Greenwood was brought into the scheme because he knew Mersereau, Lawrence said.

Lawrence said he and Greenwood went to the home, but Greenwood went in first and shot the couple with a .357-calibre Magnum handgun. Lawrence testified he then went in with a gun of his own, but Mersereau and Christensen were already dead when he shot them again.

In court, Lawrence stood and demonstrated what happened. Shooting the pair in the head, he testified, was a "good way to kill them — make sure they're dead."

Barry Kirk Mersereau, left, and Nancy Paula Christensen, right, were found dead in September 2000 in their Centre Burlington, N.S., home. (CBC Archives)

During cross-examination, defence lawyer Elise Pinsonnault pointed out discrepancies between Lawrence's testimony this week and what he said in earlier statements and court proceedings. Lawrence responded that he was telling the truth now.

After Lawrence finished his testimony, he was surrounded by police and whisked out of the courtroom.

Justice Jamie Campbell gave the jury special instructions on how they should approach what Lawrence said in court.

The judge said Lawrence has been paid by police for his co-operation. His parents were given $2,500 to help them visit him in prison. Lawrence has also received $3,600 for the prison canteen and will get another $609, plus $100 a month.

Lawrence has a criminal history dating back to 1990. He was using crack, cocaine, hash and LSD around the time of the killings, and was hallucinating.

Campbell said Lawrence has lied in the past to implicate others in crimes, but that doesn't necessarily mean he's lying now. The judge urged jurors to look for evidence that corroborates his story, but in the absence of any, they can still choose to believe Lawrence.

The trial resumes Monday. Six weeks have been set aside for the trial.

The CBC's Blair Rhodes live blogged from court in Kentville. Mobile users can read the blog here.