Crown lawyers say they will seek adult sentences for three youths found guilty in the swarming death of 19-year-old Luka Gordic in Whistler.

“When the events happened, they were close to being adults and it’s also a reflection of the seriousness of the charge,” Crown Counsel Henry Reiner told reporters Friday. “It’s fairly standard when you have a murder or a manslaughter.”

The young men, who can't be named because they were all 17 years old at the time of the 2015 attack, were handed their verdicts Friday evening by a B.C. Supreme Court judge.

One was convicted of second-degree murder, the others of manslaughter.

While reading the verdict, Justice Terence Schultes described how surveillance video from a nearby business on the night of the attack shows Gordic backing up as a group of people approach him.

A mob up of to 15 people viciously kicked and punched Gordic. The fatal blow is believed to have been a stab wound directly to the heart.

The 19-year-old victim is seen collapsing as he re-enters the frame. Based on that footage, Schultes said it appeared the attack had unfolded in as little as 17 seconds.

Emotions ran high throughout the trial, resulting in some heated arguments between relatives of the victim and the accused.

“We’re happy with the judge’s decision,” Gordic’s mother, Clara, told reporters after the hearing. “We relive this every day”

The victims’ father, Mitch Gordic, said he hopes the men will be sentenced to “many years in jail.”

Friday’s verdict was handed down in courtroom 20, which was built for the Air India trial and has an extra layer of screening, including a metal detector and bag checks.

When the judge finished reading his verdict, Gordic’s family and friend had harsh words for the families of the accused, some even banging on the glass separating the accused from the seating area and yelling at the now convicted killers.

The Gordic family will now begin preparing victim impact statements for the sentencing.

A fourth young man, Arvin Golic, was charged with second-degree murder, but convicted on the lesser count of manslaughter in June.

The court heard Golic, who was 18 at the time of the killing, did not deliver the fatal blow but did organize the beating after Gordic stood up for a young woman they both knew.

Sentencing for the three men found guilty Friday is scheduled for Wednesday, Oct. 11.

With files from CTV Vancouver's Nafeesa Karim, Maria Weisgarber and Ben Miljure