I’m willing to bet it has not much to do with that. The Coliseum BART station is located adjacent to Oakland’s biggest collection of public housing projects, populated almost entirely by African-Americans.
Well - hey! YOU Must be a raving, Trump-supporting RACIST!!!! To even suggest that, even though everything you said is 100% true... Indeed, I believe the very reason BART held this and wouldn’t release surveillance footage is because it would reveal the race of the raving pack of thugs.
It’s also the station where you get on BART if you fly into Oakland Airport, so a good place to rob travellers and grab their bags.