Cpl. Matthew Wilcox had pleaded not guilty to charges of manslaughter, criminal negligence causing death, and negligent performance of duty in the death of 25-year-old Kevin Megeney of Stellarton, N.S.

He was also found guilty on the charge of negligent performance of duty, but the manslaughter charge was stayed by the military jury hearing the case.

In his instructions, the military judge, Cmdr. Peter Lamont, told the jurors they should use “common sense” in determining which theory to believe on what happened on March 6, 2007.

The defence has argued that Wilcox, 24, of Glace Bay, N.S., was acting in self-defence, because he believed Megeney pointed his pistol at his back and readied it to fire.

But prosecutors argued Wilcox was playing a game called quick draw when his pistol was fired, basing its accusation on the testimony of several friends Wilcox spoke to after the shooting.

Wilcox’s parents cried and hugged each other when the verdict was read. One of his relatives gasped and burst into tears.

Wilcox showed no signs of emotion but looked forward.

The Megeney family sat quietly as the verdict was read, his parents holding hands.

Prosecutors said that the jury shouldn’t believe Wilcox’s self-defence argument because he lacked credibility, and argued he was “evasive” and “contrived” under cross-examination.

Maj. Jason Samson, the prosecutor, also argued that the self-defence argument didn’t stand up because Wilcox admitted he didn’t look at Megeney before firing, and had agreed he had options such as fleeing from any danger he might have felt.

The defence and the prosecution say this is the first manslaughter charge to be considered by a military jury where one Canadian soldier was accused of killing another soldier during the Afghanistan conflict.

There was one other similar case, but it never went to trial.

In October 2008, a military judge adjourned court martial proceedings against Master Cpl. Robbie Fraser, who had faced manslaughter charges after a gun allegedly discharged in a military vehicle outside Kandahar, killing Master Cpl. Jeffrey Walsh of Regina.

The defence successfully argued that a ballistics report cast reasonable doubt on whether Fraser fired the fatal shot.

The military panel had a similar standard of proof as a civilian jury, with the prosecution having to prove that Wilcox was guilty beyond a reasonable doubt.

The charges of manslaughter and criminal negligence leading to death are in the civilian criminal code, while the third offence of neglect of duty is in military law.

During his instructions to the jury, Lamont said jurors could find Wilcox guilty of either manslaughter or criminal negligence causing death.

A conviction of either charge carries a maximum sentence of life in prison.

Lamont told the panel they could also find Wilcox guilty of neglect of duty, either on its own, or in combination with one of the two more serious charges.

The jury was selected by the military’s Office of the Judge Advocate General, based in Ottawa, with the defence and the prosecutors allowed to argue for or against their selection in pre-trial arguments.

Wilcox’s defence attorney Lt.-Col. Troy Sweet says the military normally selects five jurors, including one non-commissioned officer, but in this case there were only four.