Abdullah Mela decided to kill a man rather than face the humiliation of losing money in a gun deal gone wrong.

That was the motive described by Court of Queen's Bench Justice Craig Jones as the judge found Mela, 23, guilty of second-degree murder on Monday in the 2016 death of Harsimran Singh Birdi, 20.

"Mr. Mela was angry at losing $2,500," said the judge. "Mr. Mela felt diminished in the eyes of his companions."

As Jones announced his verdict, Mela's mother broke down and began hitting and scratching herself as she screamed in Arabic.

Several sheriffs escorted the frantic woman downstairs and outside, attempting to keep her from harming herself until an ambulance arrived.

Mela now faces a life sentence.

After Abdullah Mela was convicted of second-degree murder on Monday, his mother began screaming and hitting herself. She was taken outside by sheriffs, who tried to help before EMS and firefighters arrived. (Meghan Grant/CBC)

The crime took place on the night of April 6 and into the early morning hours of April 7, 2016.

Mela wanted to buy a gun and Birdi, a friend of a friend, said he would be able to broker a deal.

But the man who was supposed to sell Mela the weapon disappeared with the $2,500.

Mela blamed Birdi.

Witnesses say Mela was irritable, upset, and yelled at Birdi.

By this point, a group of friends and acquaintances were in two different vehicles in an alley in northeast Calgary, where they had tried unsuccessfully to find the man who had taken off with the money.

Birdi offered to give Mela money

Birdi offered to give Mela $1,000 that night and pay back the rest later.

But it was too late, Mela felt he looked like a fool in front of the group.

Mela shot Birdi as he sat in the back seat of a friend's SUV, then dragged the victim outside the car and left his body in the alley.

The SUV was immediately taken to a car wash and the gun was eventually buried in a rural area near Okotoks.

Jones will hear sentencing submissions from prosecutor Tiffany Dwyer and defence lawyer Andrea Serink later this year.

A second-degree murder conviction comes with a life sentence and no chance of parole for 10 to 25 years, to be determined by the judge.