Eddy Bustamante Infante, 23, of Santa Ana, was arrested Friday at his home on suspicion of aggravated sexual assault of a child.
Authorities said he's been an instructional provider and aide at Greenville Elementary School since 2015.
The investigation began when a 12-year-old girl reported being sexually assaulted by Infante during an afterschool program when she was 10 years old. She said she had not immediately reported the incident.
Detectives launched an investigation and found two more victims who also reported being sexually assaulted by Infante. So far, authorities have identified those three victims, but are urging people who know of more to come forward.
Infante was booked at Orange County Jail in lieu of $1 million bail.
Anyone with more information or who may be a victim is urged to call Detective J. Guidry at (714) 245-8530.