They gathered to express their concerns about safety earlier Sunday.
"I think our police have to get out of their squad cars and on the streets because that's where it's happening," said Riverside resident Monica Wood.
Last Tuesday night, a woman had just left the train station when a man grabbed her from behind and raped her in an alley. The suspect ran off after the attack.
Police are working with the victim on a sketch of the suspect. It's not yet clear if the woman was followed from the train or the train platform. As a precaution, extra police are monitoring the area.