Three teens were arrested for allegedly kicking an older Asian-American woman in the head at the Dale Street Green Line station around midnight Monday.
Metro Transit began the investigation when people who viewed video of the assault on social media reported it.
A youth off-camera is heard laughing and repeatedly saying “You won’t,” to another teen, appearing to coax the teen into attacking the woman.
The teen on camera walks from the platform to the woman, jumps in the air and kicks her with one leg.
Using the social media video, investigators identified the location as the Dale Street station.