College towns like Athens can be magnets for sexual predators, they said.
"There are some people who are predators the same way lions are predators around the watering hole," Oconee County Sheriff Scott Berry said. "They know there's a lot of people who are not paying attention to their surroundings and they exploit weaknesses in people's security," said Berry, who investigated rapes and assaults on college students while working for the Western Judicial Circuit district attorney's office in the 1980s.
Women were abducted and raped in eerily similar cases a year to the day apart - one on Sept. 4, 2009, and another about midnight last Saturday. Athens-Clarke police are investigating to see if the cases are connected.
In each attack, a UGA student hailed what she thought was a taxi and got into a dark-colored van driven by a Hispanic man with a mustache who took the woman somewhere and assaulted her, police said.
Police recorded no similar rapes through the year, but that could mean some women didn't report they were assaulted.
"Research tells us that sex offenders offend multiple times throughout their lifetimes, especially when there's no disclosure" by victims that lead to arrests, said Sally Sheppard, executive director of The Cottage Sexual Assault & Children's Advocacy Center in Athens.
The rapist probably targeted college students impaired from drinking, according to Cynthia Calkins Mercado, an associate professor of psychology at John Jay College of Criminal Justice in New York.
"It sounds like what's happening here is the offenders found these victims of opportunity by using this cover of being a taxi driver," Mercado said.
"Perpetrators will seek out these crimes of opportunity by looking for victims who are more vulnerable, like being drunk or alone," she said.
It's highly likely the offenders live in or near Athens or visit frequently because predators tend to look for victims where they feel comfortable and think they won't be noticed, according to Berry.
Many assaults probably go unreported because the victims are ashamed to tell someone else they've been violated, said Nancy Zechella, former executive director of Safe Campuses Now, a defunct Athens advocacy organization.
"It's the same old problem that no one wants to report they were raped because it's such a personal injury," Zechella said.
While some victims might not want their parents to know they got so drunk they couldn't take care of themselves, Zechella believes most just don't want to re-live the experience by repeatedly telling their stories to police, attorneys and potentially to a jury in open court.
"That would just be reiterating that, 'My body's not clean anymore because some guy raped me,' " she said.
The most recent rape happened the night of a UGA football home game, just like two attacks in 2007.
The details of those sexual assaults are similar - a man driving a van posed as a taxi driver and assaulted the women who asked for a ride - but police don't think the 2007 attacks are related to the more recent ones. In 2007, the victims described the driver as a white man in his 20s, and he told one woman his name was "Brad."
The victim last weekend told investigators the suspect was a Hispanic man in his 20s, about 5 feet 7 inches tall and weighing 175 to 185 pounds. He is stocky with scruffy facial hair, and speaks with an accent, police said.
A Georgia Bureau of Investigation forensic artist made a sketch of the suspect, and Crime Stoppers is offering a reward of up to $1,000 for information.