Police said the teen was standing on the sidewalk in the 600-block of North Mayfield Avenue when a gunman came out of a van and opened fire just before 9:30 p.m. Wednesday.
A neighbor, who wished to remain anonymous, was startled by the gunshots. She looked out her window and saw a dark van speed off.
"It sounded like a volley, like someone was unloading - rapid fire. It had to have been somewhere between seven and nine shots," the neighbor said.
Avant, of the 1000-block of North Monitor Avenue, was pronounced dead at 10:10 p.m. Wednesday. Police said he was not in a gang.
Avant's family would not speak on camera. But they told ABC7 Eyewitness News that he was a student at the Academy of Scholastic Achievement, which serves high-risk teens in neighborhoods on Chicago's West Side.
Investigators are talking to several people, but have not confirmed any charges.