AUBURN – The answer to the question who murdered John Graffam and James Vining will be answered by a single number: 26.2.

Peter Rodway, attorney for one of the two men accused of killing Graffam and Vining, explained the significance of that number Monday when he pointed the finger squarely at his client’s co-defendant.

It’s a rare genetic marker found in DNA, Rodway told the jury at Androscoggin County Superior Court. That marker doesn’t belong to Rodway’s client, Thomas Dyer, the lawyer explained in his opening statement.

It belongs to Gary Gauthier Jr., the defendant who sat expressionless at the table behind the one where Dyer was seated, Rodway said.

The genetic marker showed up on a pair of blue jeans and Red Sox shirt found hidden in the woods in Pownal, along with a bloodstained bat, Rodway told the jury. Blood spatter on the pants and shirt suggest the clothes were worn by somebody who was in close proximity to and facing the victim, Rodway said.

By contrast, he said: “There’s no evidence that proves Tommy caused the deaths.”

The blood on the clothes belonged to the two victims found by hunters in Lewiston a year ago. Graffam and Vining, both from Auburn, had been buried in shallow graves near railroad tracks off Foss Road. The Office of the Chief Medical Examiner concluded both men died from blunt trauma to the head.

The trial for the murders of the two men got under way Monday. A jury of seven women and seven men, including two alternates, was picked shortly before 3 p.m.

Both defendants were in court, dressed in matching light blue buttoned-down shirts and navy slacks. Gauthier added a navy sweater vest.

Assistant Attorney General Fernand LaRochelle told jurors in his opening statements that DNA belonging to both defendants was traced to clothing found in Pownal. In some cases, it was a direct match, he said. Their DNA also showed up on empty beer bottles left in Graffam’s apartment, he said. Gauthier’s DNA was consistent with swabbings from a beer can found in one of the makeshift graves.

And it was Dyer’s defense attorney who made a more compelling case against Gauthier, leading the jury away from his client. There’s no evidence linking Dyer to the bat, Rodway said.

Gauthier’s attorney, Robert Ruffner declined to present his opening statement Monday, reserving the right to offer his version of how the evidence should be viewed later in the trial.

He had argued for separate trials earlier. But Justice Thomas Delahanty II had ruled the two cases would be joined.

The trial is expected to last the week.