It's a troubling piece of evidence but one that authorities in Reno, Nev., hope will help end the search for a serial rapist whose crime spree has gripped the casino town with fear.
Four days after the body of 19-year-old Brianna Denison was found in a vacant field in southeast Reno, authorities announced that they found a distinctive pair of women's thong-style underwear near the college student's body. The dark-colored panties, which featured stitchings of the Pink Panther as well as pink hearts, did not belong to Denison.
"The underwear is very distinctive," the Reno Police Department said in a Tuesday evening release. "It is described as having the caricatures of the head of the Pink Panther and hearts on a black cotton field."
Forensic evidence analyzed by the Washoe County Sheriff's Office showed that the underwear had traces of DNA from another unknown female, as well as DNA from the man suspected in Denison's disappearance and at least three other sexual assaults in recent months. The connected attacks have police convinced a serial rapist is at work in Reno, targeting college-aged women.
"It could have been left by accident or fell out of the car when he unloaded Brianna," Reno Police Lt. Robert McDonald told ABC News. "Or he may have left it behind on purpose. We don't know for sure."
McDonald said that Reno police are considering the possibility that the suspected rape and murder suspect is intentionally taunting authorities. While it is impossible to say for sure that the underwear was left as some kind of message, McDonald said there's no doubt about the urgency to make an arrest.
"This man is dangerous," McDonald said. "There is nothing more dangerous I can think of as a predator who prowls at night and looks for crimes of opportunity. And he's preying on women who are substantially smaller and weaker than he is."
Compounding the alarm for authorities is the knowledge that the suspect's crimes are escalating in severity. First were two quick sexual assaults in public places. Then, the suspect allegedly took a victim in his vehicle to a secluded place and raped her before dropping her back near her house.
The Denison case is the most frightening and bold crime yet, with the suspect entering a house rented by one of the victim's college-aged friends in the early morning of Jan. 20 and abducting Denison only for her body to be recovered nearly a month later.
The autopsy on Denison's body found that she had been strangled. She had been in the field, about 8 miles from the house where she was last seen, for more than a week, concealed by a recent snowfall.
Her death, authorities said last Friday, was the work of the same serial rapist suspected in the previous attacks.
Last month, University of Nevada-Reno police released a sketch of the suspect based primarily on descriptions provided by the victim who survived her abduction. He is 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.
The man was driving a large vehicle, likely an extended cab pickup that requires a step to climb into. There was a baby shoe on the floor of the vehicle and paper strewn about. In all of the instances, the suspect was wearing casual clothing, such as a hooded sweatshirt or jersey and warm-up style pants.
The discovery of Denison's body touched off a new spurt of tips to the Reno police, who had to double the number of personnel working the tip lines. Reno police also have support from university detectives as well as the FBI.
Community donations have allowed authorities to expedite DNA testing, and McDonald said that all of the DNA collected as part of the Denison investigation had been processed. The police department's larger backlog of DNA processing has also been farmed out.
The hope, McDonald said, is that one of the profiles will match the DNA connecting this spate of crimes and provide authorities with the identity of the suspect. A silver lining, McDonald said, could be a break in another one of the department's cold cases.
Authorities continue to release new information in the case in large part because they believe the suspect -- or in this case, the Pink Panther underwear -- is known to someone in the Reno area. There's a chance the suspect could have fled the area, but McDonald said they are working under the assumption that he remains somewhere in Reno.
Either way, McDonald said, the suspect needs to be found to ease increasing tensions the alleged crimes have created.
"Until this guy's behind bars, there's going to be heightened awareness in the area," he said.