TAMPA — Jordan Lewis was walking fast down a main street on the University of South Florida's campus after dark when she heard the man's voice:
"Don't walk alone little girl. You're going to get raped."
The words stopped Lewis in her tracks Monday night. She glanced at a car pulled over at the curb but saw only shadows.
That's when she ran.
Pepper spray clutched tightly in her hand, the 24-year-old Lewis didn't stop until she reached her on-campus apartment building.
Even then, she didn't feel safe.
In the past three weeks, two unrelated rapes have been committed in on-campus residence halls.
The first time, the attacker was a stranger. The most recent rape was a more common crime: The victim knew her attacker.
"It's terrifying," said Lewis, a senior engineering major. "I think about it all the time."
She's not alone. Students across the campus have changed their behavior in the weeks since the first assault, which happened Sept. 19 inside a co-ed freshman dormitory.
Students with night classes have started to buddy up on trips across the campus. Some have begun unplugging from iPods and cellphones while walking. Many people living in residence halls no longer allow strangers without student IDs to follow them inside.
Caisey Bluck, 19, changed her parking lot pass so she wouldn't have to walk as far from her car to her dorm.
"You always hear these statistics about rape on college campuses, and then there it is — in the building right next door," Bluck said. "You realize, oh my God, that could be any of us."
Last year, one person reported being sexually assaulted on the USF campus, down from seven in 2010.
So far this year, four cases have been reported to police.
Neither of the first two cases, which happened during the spring semester, were prosecuted. In both cases, the victim knew her attacker, police said, but that's often not enough for prosecutors.
University officials said police statistics tell only part of the story. More reports do not necessarily mean more rape.
"We haven't seen an increase in sexual violence," said Nanci Newton, director of USF's victim advocacy program. "We're seeing an increase in victims willing to come forward and report the crime. That's a good thing."
On a campus of about 40,000 students, experts say, hundreds will be sexually assaulted each year. The vast majority of incidents will never be reported. That's partly because the victim often knows her attacker, according to experts.
That was the case on Sunday, police said, when a man raped a female student in Epsilon Hall, a co-ed freshman residence that houses about 240 students.
Although the victim identified her attacker, police have not made an arrest.
The more unusual crime, officials said, was the Sept. 19 rape, when a man attacked a female student just before 7 p.m. inside a vending machine-laden area of Kappa Hall, also a co-ed freshman dorm.
"It's scary to think he's still out there," Bluck said. She and several of her friends have begun "looking around at people, wondering, 'Could that be him?' "
To quell fears, particularly among freshmen, university police have increased patrols near residence halls, Lt. Charlotte Domingo said.
The university has not installed cameras inside or outside the residence halls and has no plans to do so, said Ana Hernandez, dean of housing and residential education.
Students who work in the dorms as resident assistants have been asked to be extra vigilant in their daily patrols.
But some say that's not enough.
David Earnest, 20, lives in an off-campus apartment. In his walks to and from school, the junior computer science major hasn't noticed more police where he said they're most needed: on the campus perimeter.
"This is an urban campus in the middle of Tampa," he said. "Crime spills on campus, and we don't have the police presence to stop it."
So, Earnest said, he's been doing what he can to help by walking female classmates to and from their homes and keeping an eye out for the Sept. 19 rapist, who remains at large.
According to police, he is white, 18 to 22 years of age, close to 6 feet tall and 180 pounds with a muscular build and short black or shaggy brown hair. He was last seen wearing a dark gray T-shirt, green cargo shorts and flip flops.
University police have asked anyone with information about the rape to call them at (813) 974-2628.
Staff writer Jessica Vander Velde contributed to this report. Marissa Lang can be reached at email@example.com or (813) 226-3386 or on Twitter @Marissa_Jae.