RENO, Nev. -- Police disclosed for the first time on Thursday that a second pair of women's panties found with Brianna Denison's body had DNA belonging to her, the man who killed her and a woman who lived at the house from where she was abducted.

The second pair, which police did not describe, was intertwined with the previously disclosed thong-style underwear that is black with Pink Panther emblems, Reno police Commander Leigha Struffert said.

Investigators believe both pairs may have been taken from the home where Denison last was seen when she was abducted Jan. 20 on the edge of the campus of the University of Nevada, Reno, she said.

"This is going to be critical in this case," Struffert told reporters. "They were intertwined and found at the scene of Brianna's body."

Denison, a student at Santa Barbara City College in California, was visiting her hometown over winter break and was last seen sleeping on a couch at a friend's rental house just off campus.

Two women and two men lived at the house. All have been interviewed and none is considered a suspect, Struffert said.

She did not say why police had previously kept secret the discovery of the second pair. She said they decided to publicize their existence on Thursday to clear up confusion about the presence of DNA on the Pink Panther pair.

Police originally reported the first pair had DNA from the suspected killer and an unknown woman.

But Reno Police Lt. Robert McDonald said earlier this week that DNA belongs to an unknown male and female.

Police said DNA evidence links Denison's kidnapping to two other attacks on women near the university late last year, and that an earlier on-campus attack also could be related. In that earlier incident, the attacker was so brazen he raped a woman at gunpoint in a parking garage where campus police park their cruisers.

Based on partial descriptions from previous victims, police have described the suspect as a white male between the ages of 28 and 40 who is at least 5-foot-6, with a long face and brown hair. He was believed to have normal speech with no accent or regional dialect.