The attack occurred Sunday at the light-rail station near the intersection of Washington and National boulevards, the Los Angeles County Sheriff's Department said in a news release.
Roderick Moore, 36, was taken into custody the same day and remained in custody Wednesday, the statement said.
The Los Angeles County district attorney's office filed two counts of sexual assault in the case, authorities said. Moore's bail was set at $210,000 with a pending court date.
"Based on the nature of the allegations, detectives believe there may be additional unidentified victims," the news release said, without providing additional details. "Detectives are seeking the public's help in identifying any such victims."
Disturbing video shows man trying to toss woman into oncoming traffic in random attack in Pasadena
Disturbing video shows man trying to toss woman into oncoming traffic in random attack in Pasadena
Anyone with information about the case is asked to call the LASD Special Victims Bureau toll free tip line at (877) 710-5273 or contact the agency by email at specialvictimsbureau@lasd.org.
Sunday's incident occurred more than a week after a man brutally attacked a woman at the Metro A Line station in Pasadena. That attack was captured on surveillance video, which shows the assailant throwing the victim into the path of oncoming traffic on the adjacent 210 Freeway. Although seriously injured, the woman was apparently not struck by a car.
Juan Flores was arrested the same day and charged with attempted murder.
L.A. County Supervisor Janice Hahn issued a statement Wednesday.
"While I appreciate that law enforcement has been able to respond quickly to these recent incidents, not enough is being done to prevent these attacks from ever happening in the first place," Hahn said. "My question is: where were uniformed law enforcement officers assigned to Metro and transit security officers while these attacks were happening? And what will Metro do differently now to prevent violent crimes in the future, like installing technology to detect and keep weapons out of our system?"