CTV News has learned a daylight shooting that claimed the life of a 19-year-old on Saturday was the result of a dispute with two other individuals outside a flea market.

Homicide investigators have reviewed surveillance tape from Dr. Flea's flea market on Highway 27 and are looking for two men, now considered prime suspects, in connection with the daylight shooting.

Jose Hierro Saez died after being shot in the head on Saturday afternoon while riding in a car that had been sprayed with bullets on John Garland Boulevard, near his home in the Jamestown complex in Rexdale.

Three other men, 20-year-old Moustaffa Omar and 18-year-olds Paddy McFinn and Matthew Dale, were also hit by gunfire. They were taken to hospital with non-life threatening injuries.

Police believe the suspects fled the scene in a silver late-model Mercedes-Benz SUV.

Investigators said they don't have reason to believe the incident is gang-related.

The three surviving victims of the shooting are refusing to co-operate with police.

"Those individuals are clearly involved in conduct which has lead to some of the violence in our communities and so they are not people who are normally going to cooperate with the police," Police Chief Bill Blair said on Monday.

Blair said he is concerned the recent escalation in gun violence could lead to another "summer of the gun," but police are doing everything they can to get illegal weapons off the streets.

"We gained some additional resources yesterday in order to put even more people on the street and they'll be out there very shortly working in our communities," Blair said.

"We have the means, we know we have a successful strategy and we're going to continue to work hard on it.

Residents in the Rexdale community were reluctant to speak with the media on the weekend. Some said they stick to the "no snitching" code of silence because they don't trust police and fear retaliation.

Toronto police have been frustrated with similar investigations recently.

Omar Wellington, 17, was beaten to death by a group of people in the Flemingdon Park area last summer in front of many witnesses of a nearby apartment building, but they too refused to come forward and co-operate with police.

It wasn't until nine months later that police received crucial information and were able to make a number of arrests in the grisly gang-related murder.

Last summer, anti-snitch T-shirts circulated through the gang and gun-plagued Jane and Finch community.

The shirts threatened witnesses to crimes. They read: "If you give tips on guns and gang crime, you'll end up missing!" and "Stop snitching or end up in Sunnybrook."

Mourners remember slain youth

The victim of the weekend shooting was described as a polite boy that didn't seem to have any enemies.

"He was a fun guy to be around. He didn't have no problem with nobody," said one young man.

"I still don't believe it. He was a really, really nice kid. He had a lot of respect. He'd come over to your home, he'd take your shoes off, he'd always say 'hi'," said another resident.

Friends and neighbours laid flowers on Sunday metres from where Saez was gunned down.

Saez's mother, who collapsed in tears when hearing the news of her son, allowed a reporter in her home on Sunday but wouldn't speak about the incident.

Blair said shootings are down 40 per cent this year over last.

He  announced additional funding on the weekend that will keep more officers in the downtown entertainment district.

Premier Dalton McGuinty said he would like to see a provincial review of what's being done to fight gun violence. He also wants a handgun ban in Ontario.

The shooting in Jamestown prompted McGuinty, Mayor David Miller and federal NDP Leader Jack Layton to reiterate calls for Ottawa to do more to reduce to stop the guns coming to Canada from the United States.

With a report from CTV Jim Junkin