ASU police are looking for a male subject who entered a ground-floor University Center women's restroom on the downtown Phoenix campus around 8 p.m. on Tuesday.
The department tweeted a crime alert about the incident on Wednesday afternoon, urging anyone with information to contact ASU police.
"The male stood on a toilet, looking into a female occupied adjacent stall," the alert stated. "The female noticed the male looking into her stall, prompting the male to exit the bathroom."
The alert described the subject as a 5-foot-4-inch black male in his early 30s carrying a backpack and wearing a white T-shirt, tan pants and white sneakers.
A witness saw the man then exit the west side of the building toward Central Avenue, according to the alert.
ASU police department spokesperson Katy Harris said there are currently no further details on the subject's description.
Anyone who has information relating to this incident should call ASU police at 480-965-3456.