Reno police say the man they arrested for allegedly raping and murdering a 19-year-old college student may be responsible for other sexual assaults in the area and in Washington state.
Reno Police Lt. Robert McDonald told ABCNews.com that they were led to James Michael Biela, 27, after an anonymous tipster called earlier this month to report that Biela's girlfriend, the mother of his 4-year-old son, had found another woman's underwear in his truck's console.
Underwear has played a key role in the investigation into the death of Brianna Denison, who disappeared from a friend's rental house on Jan. 20. Her body was found in a vacant field in southeast Reno the next month, with two pairs of panties that did not belong to the teen found nearby.
"We believe he assaulted her to the point of unconsciousness right there in the house ... and then removed her," McDonald said.
In addition to the murder charges in Denison's case, Biela has also been charged with sexual assault and first-degree kidnapping in the Dec. 16, 2007, attack on a Taiwanese exchange student identified as Hsiaotzu C. in the affidavit.
McDonald said that Biela refused to take a voluntary DNA test. So police tested his young son with the cooperation of the boy's mother.
"That DNA sample matched," he said.
Police arrested Biela Tuesday evening. A subsequent DNA test taken from him today matched the samples taken from Denison's body, police said. His DNA was also found on the handle of the door at the rental house, which had been left unlocked.
Efforts to reach counsel for Biela were unsuccessful.
McDonald said Biela left Reno shortly after Denison's body was found and police put out description of a vehicle matching his. He later sold his truck and took a job in Washington state.
It was when he was returning to the area in mid-September that his girlfriend found the panties in his console.
McDonald said they do no know who those panties belong to, or whose were one pair found near Denison's body with designs of the Pink Panther character and hearts. He said police know who the second pair found with Denison's body belong to, but that they are not releasing the identity of the woman.
McDonald said Reno police are now checking with authorities in Washington state to see if any crimes there match with Biela's DNA. There was also a third attack, an attempted sexual assault on Nov. 13, 2007, that has DNA linkage to the cases of Denison and Hiasotzu C. -- but no charges have been filed in that case.
"We want to see how things progress with these two cases first," McDonald said.
The autopsy on Denison's body found that she had been strangled. She had been in the field, about eight miles from the house where she was last seen, for more than a week, concealed by a recent snowfall.
Police were called to the house on Jan. 20 after Denison's friend came downstairs to where the teen had been sleeping and found a bloodstain the size of a "silver dollar" on the pillow she had been using.
It appeared Denison had disappeared wearing no shoes and only the sweats and a light shirt she'd worn to bed. Her cell phone and purse had also been left behind.
Denison was from the Reno area but was attending Santa Barbara City College in California when she was murdered.