WINNIPEG -- Police believe the killer of three men who lived on Winnipeg streets was homeless himself.

John Paul Ostamas is accused of two counts of first-degree murder in the weekend deaths of Donald Collins, 65, and Stony Bushie, 48. He is also facing charges of second-degree murder in the killing of Myles Monias, 37, following an assault in a bus shelter earlier this month.

Supt. Danny Smyth said Collins went into a laneway Friday night with Ostamas where police believe Collins was attacked and killed.

"He was left for dead in the alley," Smyth said at a news conference Tuesday.

Hours later, Smyth said, Ostamas encountered Bushie and they went to a downtown parkade.

"Ostamas attacked and murdered Bushie within the parkade and left him for dead," Smyth alleged.

Ostamas is originally from Thunder Bay, Ont., but was staying at a Winnipeg homeless shelter.

Following the killings, police released security footage featuring a "person of interest," who turned out to be Ostamas. He knew both Collins and Bushie, Smyth said.

"I wouldn't say they were friends," Smyth said. "There is no motive that I'm aware of."

Winnipeg police didn't have much contact with Ostamas, but he has a record that includes multiple assaults in the Thunder Bay area dating back to 2002, said Smyth. Detectives are working with investigators in other jurisdictions to determine if Ostamas should be considered a suspect in other crimes.

Ostamas had yet to appear in court on the murder charges.

The weekend killings sent a chill through the homeless community as police warned people living on the streets to be careful.

Mark Stewart, residential manager with Winnipeg's Salvation Army, said everyone is mourning both the victims and their alleged killer.

"This person was also a part of this community so, at one point, he was involved with the community. He was friends with people," he said. "Everybody is really surprised and kind of heartbroken right now."

Lisa Goss, executive director of The Main Street Project shelter, said the arrest of a suspect brings a certain relief to Winnipeg's homeless, but it's temporary.

"The reality is, they're prepared for this every day," she said. "It is a different way of life when you don't have the securities that you and I do."

Martin Owens grew up with Bushie on the Little Grand Rapids First Nation northeast of Winnipeg. Bushie lived on the reserve during the winter and had just travelled to Winnipeg two weeks ago.

"He was always a happy kind of guy, always joking around," said Owens, chief of the First Nation. "He would come out (to Winnipeg) and hang out with his friends and then go home. He just wanted to see his friends again."

Owens said he saw Bushie a few days ago and offered to pay his way back to Little Grand Rapids any time he wanted to go home.

Bushie loved hunting and fishing, he said. Bushie's mother taught him to live off the land and he was heartbroken when she died around 10 years ago, said Owens, who added Bushie is survived by an older brother and sister and never had any children.

His violent death is a shock, Owens said.

"I don't even know how to describe it. He will be missed."