The shooting happened around 4 p.m. in the 4400 block of Turquoise Street. Two officers were in the area on a routine patrol, according to the LAPD, when they encountered a suspect they believed was armed.
The officers stopped the teen, and at some point a scuffle broke out and the officers opened fire.
The suspect was struck and no officers were injured, authorities said. A handgun was recovered at the scene.
The teen was transported to a local hospital and underwent surgery. He was listed in critical condition in the ICU.
A witness at the scene said she saw police cars parked in her driveway and heard a struggle outside. She said she looked out of her window to see at least two officers struggling with the suspect and then he was shot.
Authorities said the suspect is 18 years old.
Another witness said she saw what unfolded from down the street.
"So I've seen the cops pull him over for no reason. They pulled him over and I guess they asked for his ID. He didn't have ID so they tried to pat him down and I think he made a wrong move so they felt threatened and I think they shot him three times," witness Bertha Hernandez said.
Investigators are also looking into a prior handgun-related arrest of the teen in the last few weeks.
The investigation was ongoing.