Winnipeg police said yesterday they picked up the three suspects Friday night and they remain in custody.
Morgan Trudeau, 18, died early Friday after he and a 19-year-old friend, Scott Fraser, were attacked -- possibly with rocks and bottles -- while walking home from a Pembina Highway hotel.
The three males arrested Friday have been charged with two counts of assault with a weapon.
Police said they expect to lay further charges once the cause of death is determined.
The name of the 18-year-old suspect has not yet been released and by law the two 17-year-olds cannot be identified.
Police said Trudeau and the other victim, who was identified by Shaftesbury High School students as Scott Fraser, had been involved in an altercation with three other males near Pembina Highway and Jubilee Avenue before the final confrontation.
The trio was seen following Trudeau and Fraser to Parker Avenue and Wynne Street, where the attack took place.
Fraser was not seriously injured in the attack.
A friend, who was drinking with Trudeau and Fraser at the hotel before the killing, said they weren't out to make trouble.
"We were quiet. There weren't any arguments. There was never any violence." He seemed baffled by what happened.
"This is the first time anything like this has hit so close to home," he said. "We were relaxed and we kept to ourselves."
The friend said he left the hotel before Trudeau and Fraser and can't imagine what went wrong. "I don't know what he was doing there at 2:30 in the morning."
Trudeau's step-grandmother sounded equally mystified yesterday.
"I really can't believe he's gone," said Lorraine Trudeau, who hadn't seen Morgan -- whose parents are separated -- in nearly a year.
"Because of the split, it's been tough. We haven't been able to see him."
Lorraine Trudeau said her son Dan, step-father of the slaying victim, flew in yesterday from Edmonton.
Trudeau's mother and her children, including Morgan, moved late last summer into a rental property in the Charleswood area.
No one answered the family's door yesterday and there were signs no one had been there in some time.
Flyers and mail were stuffed to overflowing in the mailbox and jammed inside the outer door of the front entrance.
The family's next-door neighbour said yesterday that she rarely saw the Trudeaus, but when she did the mother seemed pleasant and the kids were always friendly.
An older-model vehicle with a flat tire that was parked at the address was Morgan Trudeau's, the neighbour said.
Trudeau, a high school dropout who last attended class at Shaftesbury High School in Tuxedo in 2002, is the city's 10th homicide victim this year.
He was the third city teen to be beaten to death in less than a month.
On May 11, 19-year-old Johndrick Tan was beaten to death outside an Exchange District nightclub. Four suspects have been charged with manslaughter in connection with Tan's death.
And on June 2, John Chubb, 15, was beaten to death with a baseball bat outside a popular inner-city concert club. Police charged a man with murder in that case.