Two men are on trial, accused in the stabbing death of Albert Lowenberger outside a Regina bar. (CBC)

A jury has begun deliberations to determine the fates of Ronald Zerr and Ashton Lavallee, both on trial in relation to the death of Albert Lowenberger at a Regina bar four years ago.

Zerr is charged with second-degree murder. Lavallee was initially charged with murder as well, but the judge has reduced the charge to manslaughter.

After a three-week trial, the jury spent Monday listening to detailed instructions from the judge.

They began deliberations after a supper break, and called it a night after about an hour.

They were expected to resume pondering the case Tuesday morning.

During the trial, the jury of eight women and four men heard some witnesses say that Lowenberger was the victim of an unprovoked attacked.

The two accused also testified, claiming they were defending themselves in a fight that erupted at an exit to the King's Head Tavern.

Lowenberger died of a stab wound to the heart.