The man has attempted to fondle at least four women who were either walking or jogging near campus, The Denver Post reported Monday.
Police released a composite sketch of the man who groped a woman Thursday night.
The victim reported she was walking near the university when she passed a man on the street. She said she then heard footsteps of someone running behind her. She turned around when the man she passed grabbed her buttocks.
She yelled at the man, who then ran off.
The frequency of the attacks is causing concern on the DU campus, particularly with women.
"It's definitely scary," said Junior Jenni Talcott, a criminology and psychology major and the president of the student group Rape Awareness and Gender Education. "It's 9 o'clock at night, and you're walking down a street that you always walk down, and there is this guy who is targeting us."
The university sends out campus-wide e-mail alerts whenever an incident occurs.
"I think they just write [the e-mails] off. The male population ... I feel that they don't worry as much," Talcott said. "We try to tell them that 1-in-4 women in their lives will be a victim."
The suspect is described as a white male, about 19 years old, 5 feet 8 inches with a thin build and wearing a dark gray sweatshirt with black stripes down the arms.