A retired Manitoba soldier faces the possibility of life in prison after being convicted of four charges stemming from a deadly training accident in Afghanistan.

A court martial panel on Thursday found retired warrant officer Paul Ravensdale guilty of breach of duty causing death, breach of duty causing bodily harm, unlawfully causing bodily harm and negligent performance of military duty.

The five-member panel — akin to a jury in a civilian trial — found Ravensdale not guilty of manslaughter and a second count of negligent performance of military duty. "What I hope (the verdict) would do is cause others to think twice and to reflect on the nature of what they're doing ... and to take further steps to keep their soldiers safe," prosecutor Maj. Tony Tamburro said after the hearing.

Ravensdale was leading a test of C-19 anti-personnel mines on a weapons range near Kandahar city in February 2010 when one mine misfired and sent hundreds of steel ball bearings in the wrong direction. Instead of fanning out forwards, the ball bearings shot backward, directly toward soldiers who were watching. Some of the projectiles hit and killed Cpl. Josh Baker. Four other soldiers were injured.

Ravensdale appeared to take in a deep breath as the verdict was read, but showed little emotion.

Ravensdale's lawyer, Maj. Philippe-Luc Boutin, pointed to testimony from witnesses who said Ravensdale had told them to stay behind a row of light armoured vehicles during the exercise. The court martial heard that some stood between vehicles or on top of them and Ravensdale gave the order to fire anyway.

Boutin said Ravensdale was disappointed with the verdict. "We expected another outcome, but this is what the panel has decided and we'll have to live with it."

A conviction of breach of duty causing death carries a maximum sentence of life in prison, although both the prosecution and the defence said Thursday they had not yet decided what sentence they will seek at a hearing set for March 4.

Maj. Darryl Watts, one of Ravensdale's superiors, is awaiting sentencing on charges of negligence and unlawfully causing bodily harm. Another superior, Maj. Christopher Lunney, was recently demoted to captain and given a severe reprimand after pleading guilty to negligent performance of duty.