TORONTO — — Police were investigating the possibility of gang involvement in a shooting that killed two and injured 21 at an outdoor party, and said Tuesday they were concerned about the potential for violent retribution.
Bullets from more than one gun sprayed into the crowd of more than 200 people at an annual barbecue Monday night in the suburb of Scarborough. Police said two handguns were used, and one was recovered at the scene.
“In my 35 years of policing, this is the worst incident of gun violence in my memory,” Chief Bill Blair said. Authorities said they had one “person of interest” in custody and were looking for other suspects.
In the second public shooting in Toronto in less than two months, a 14-year-old girl and a 23-year-old man were killed. A 22-month-old infant was grazed by a bullet, but the injuries are not life-threatening, Blair said. One man was undergoing surgery and remains in critical condition. Others were treated and released from hospital.
Monday night’s shooting came just weeks after a gunman opened fire in a crowded food court at a busy mall in the heart of the city. One man was killed instantly at Toronto’s Eaton Centre, another died days later and several bystanders were sent to the hospital.



