The jury trial for a man accused in the stabbing death of Brett Wiese at a house party over six years ago started in a Calgary courtroom on Monday.

Wiese was stabbed multiple times while attending a party at a home in the Brentwood area in January of 2013.

Mitchell Harkes was charged with second-degree murder.

He was convicted by a jury along with another teen who was also convicted of second degree murder for her role in Wiese's death.

Harkes appealed the decision saying that there were errors in the judge's instruction to the jury.

The Alberta Court of Appeal agreed and granted Harkes a new trial.

On Monday, Harkes, 25, pleaded not guilty to second-degree murder when he was arraigned.

Crown Prosecutor Carla MacPhail presented her opening statement and said that Wiese was stabbed seven times; six times by Harkes and once by another person, who can’t be named because of a publication ban.

Justice Robert Hall and 12 jurors are hearing the case. The trial is scheduled for four weeks.