A Mexican Uber driver living in the U.S. illegally was charged Monday with raping, assaulting and robbing young women in California, prosecutors said. Alfonso Alarcon-Nunez's four alleged victims are between 19 and 22 years old and three were intoxicated when they were assaulted, San Luis Obispo County District Attorney Dan Dow told reporters. Officials said Alarcon-Nunez was not always driving for Uber when he picked up those women but said the alleged crimes show that the company should improve its driver screening process, Dow said.