Christian Aceves, 32, was taken into custody on Monday.
The woman told police that she met the suspect online and agreed to meet him in person in Alhambra. When she arrived, Aceves allegedly pulled out a weapon and threatened to harm her. Police say he then drove the victim to a secluded area and sexually assaulted her.
Detectives believe there may be additional victims who have not yet come forward.
Anyone who may have been a victim or who has information about this investigation was asked to contact Detective Huezo with the Alhambra Police Department at (626) 570-5159.