Another passenger Wiseley Wu, who was sitting nearby in the train, captured the incident and uploaded it on Facebook.
According to the SFWeekly, a man who identified himself as Charles Wu, said he was the passenger harassed on Monday night, said the assailant got on the train near the Coliseum Station and was talking loudly about the Warriors' Stephen Curry.
The assailant then started to loudly use a racial slur, Charles Wu said, which prompted him to tell the man to stop.
BART police officials said they were investigating the incident. (ANI)