That victim described the suspect as roughly in his 30s, with a square chin and muscular build. He had an "innie" belly button, police said, and had shaved his pubic hair. He had some facial hair, did not smell of alcohol, cigarettes or cologne, and spoke with no noticeable regional dialect, according to the victim.
In all four instances, the suspect was wearing casual clothing, like a hooded sweatshirt or jersey and warm-up style pants. The crimes, authorities say, do seem to be escalating in their nature.
Brianna Denison disappeared on early Sunday morning, Jan. 20. She sent a final text message at 4:23 a.m. after returning from a party in the city.
A friend woke up about five hours later to find that Denison, who had been sleeping on a couch near an unlocked door to the rental property, was gone and a silver-dollar size trace of blood had been left behind on her pillow. Tests later showed that it was Denison's blood.
It's been nearly two weeks since Denison vanished and while her family, friends and authorities try to remain hopeful, the situation is grim. "Every day that goes by, it's worse," McDonald admitted.
Todd Renwick, the associate director of the University of Nevada-Reno police services, told ABC News that students as well as members of the broader campus community are "losing sleep" over fears of being the suspect's next target.
"We have to try to calm down the campus," Renwick said, adding that they are fielding far more calls from concerned students than ever before. That's both a good thing and a bad thing, he explained. On the one hand, students are being more vigilant. On the other, students are clearly frightened.
"When you look at the overall scheme, you can still say the campus is safe," he said. "But we have thousands of people who are frightened to go from Point A to Point B."
The Reno police department continues to follow up on "hundreds" of leads. They have interviewed sex offenders in the area and have asked some men identified through tip lines as possible suspects to submit voluntary DNA samples, which he described as an "easy, quick, unobtrusive process" for eliminating someone.
Authorities are urging members of the Reno public to watch for subtle changes in behavior and appearance that may tip off a suspect. They say that the man may be an unlikely match for the crimes, living an otherwise seemingly normal life with a wife or a girlfriend.
The case has become a central focus for the Reno Police Department, McDonald said, with signs hanging around the station that read "Find Bri," short for Denison's first name. It also has trained a spotlight on a backlog of DNA samples submitted by criminals and suspected criminals in Washoe County that have not yet been logged into the law enforcement database.
Already, donations have come forward from local businesses to cover the estimated $200,000 price tag needed to end the backlog by hiring an independent lab to handle the DNA processing. Still, McDonald said, that process will take up to two months. Money has also been made available to turn around DNA samples involved in the suspected serial rape case within two days.
While the cause for concern is obvious, McDonald said, they are intent on finding the man they believe is responsible for the string of sexual assaults. "We will find this individual," he said. "If it is not tomorrow, this week, this month or this year, this guy will pop up.
"There is no statute of limitation on this."