Officers responded to the sound of gunshots at around 1 a.m. Thursday at an apartment building near the corner of Jane Street and Highway 401 on the city’s northwest side.
They found a 16-year-old in the stairwell suffering from gunshot wounds, and he was pronounced dead at the scene.
Police say three male suspects were seen fleeing the area in a dark-coloured Honda.
Investigators are looking to speak to anyone with information about the shooting, which police say is the city’s 35th homicide of 2019.
It happened the day after a group of Somali mothers who have lost loved ones to violence made a presentation to the Toronto Police Services Board, calling for the city to do more to address a wave of shootings.