The suspect has been snapping pictures of women in campus bathrooms. The most recent incident happened Wednesday on the third-floor bathroom of Manzanita Hall.
The woman spotted the suspect and chased him to a parking structure, where he disappeared.
The young man has allegedly been entering women's restrooms and reaching over the stalls to take pictures of women with his cell phone before fleeing.
Similar incidents were reported on Oct. 16 and Sept. 16.
The suspect may also be connected to a series of incidents in which women were cornered by four suspects who made sexual comments and tried to grab them before they escaped.
CSUN student Joyce Abarca says she's concerned for her safety.
"I come to school thinking I'll be safe, then this happens and it's quite scary," said Abarca. "None of us are going to go to the bathroom alone anymore; we're going to go in groups."
Police have no solid description of the suspect, but they are warning women to be on the lookout.
Anyone with information on the suspect was urged to contact campus police at (818) 677-3826.