A teen who attacked another passenger on a Green Line train on Monday has been charged with assault today, Metro officials say.

A video, originally posted by Twitter user @DeefrmUpt, shows the teen being egged on to attack the man, went viral. In the video, one person tells the assailant, “You don’t do it, you’re a bitch. It’s just straight like that.” After the teen assaulted the man, the victim turned around and responded, “What the fuck is wrong with you?” The others close in around the victim, taunting him to “say something else.”

The assailant and his friends are black and the victim white. Trump supporters and white nationalists in the internet cesspool known as 4chan picked up on the racial dynamic, which prompted the video to go viral, according to Washington City Paper.

The attack happened at 12:10 p.m. Monday near Prince George’s Plaza, Metro spokesman Richard Jordan told DCist. The teen has been charged with second degree assault. As a minor, his name isn’t being released and officials still don’t know his exact age.

Last night officials sent out a tweet asking for help finding the assailant, and then this morning, they tweeted out that they had made an arrest: