An extensive search has turned up no new clues to the disappearance of a 19-year-old college student last seen sleeping near an unlocked door, police said Wednesday.
Officers questioned a man who had given Brianna Denison's friend a ride home the night before she disappeared, but said he is not a suspect.
"We have spoken with the person who was driving the Suburban that we were looking for originally and he is not involved in the case," police Cmdr. Ron Holladay said Wednesday in an interview with CBS' "Early Show."
Denison, visiting her hometown during a a winter break from her school in California, was last seen at 4 a.m. Sunday. Police said she had been sleeping on a couch near an unlocked glass door after a night of partying. When her friends awoke later that morning, she was gone " but her clothes, purse and cell phone were left behind.
"All the indicators are that Brianna has been abducted," Holladay said. "It is our sincere hope that she'll come walking in the door any minute, but the longer it goes, the less the chances are of that occurring."
Investigators with search dogs have combed the neighborhood.
"We have not discovered any shoe prints, anything that might lead us to a direction that a suspect may have taken her," Holladay said. "We have done extensive searches both with canines and also on foot and door to door, under houses, backyards, things like that and have turned up no clues."
Detectives were awaiting test results on whether a silver dollar-sized stain on the pillow Denison was using is blood.
Two of Denison's friends, Jessica Deal and K.T. Hunter, said they were making breakfast Sunday morning when they realized her personal items were still there.
"There is no way she left voluntarily," Deal said.
"Brianna was one of the most cautious and responsible friends I had," Hunter told CBS. "She would never go anywhere without her phone and ... every time she went out she was always calling her mom."
Denison, who grew up in Reno, is a student at Santa Barbara City College in Santa Barbara, Calif. Friends and family say she was at home over the winter break and had planned to return to school this week.
In the hours before her disappearance, Denison had been party-hopping at venues associated with a weekend snowboarding event, police have said.
"I just hope that whoever did this is listening and knows what a great person she is and she doesn't deserve this at all," Hunter told a Reno television station Tuesday night.
"Hopefully whoever did this sees how hurt everyone is over it, might even feel an inkling of that and return Brianna."