Early in their investigation into the kidnapping and slaying of a young college woman, Reno police were convinced the suspect they described as a serial rapist was a chameleon who blended in with a community grieving the loss of Brianna Denison.

"Likely he looks like somebody you would least suspect, but that is the person who is responsible for this crime," Deputy Police Chief Jim Johns said in February, a day after Denison's body was found.

On Wednesday, the profundity of Johns' words emerged when police announced the arrest of a 27-year-old construction worker.

James Michael Biela, a former Marine who trained in martial arts at an academy frequented by law enforcement officers, was arrested Tuesday afternoon while picking up his 4-year-old son from preschool.

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"He seemed like a nice, normal guy," Cindy Stern, a neighbor of Biela, told the Reno Gazette-Journal. "I guess killers don't wear a sign."

Biela's arrest followed a tip, one of more than 2,200 received during a 10-month investigation, that came after Biela's girlfriend, Carleen Harmon, confided in a friend about the couple's relationship troubles and recently finding a pair of woman's underwear in his vehicle, police said.

Biela is charged with murder in Denison's death, as well as kidnapping and sexual assault for an alleged attack on another woman in December near the University of Nevada, Reno. That victim was able to give police a partial description of the suspect and a vehicle.

She also said her assailant kept her underwear.

Detectives said Biela initially declined to provide a voluntary DNA sample, but Harmon allowed police to take a DNA sample from the couple's son. From that, forensic experts determined the child's biological father could not be ruled out as the source of DNA evidence gathered from the crime scenes.

Police later obtained an arrest warrant for Biela and authorization from a judge to seize a DNA sample that investigators say matches crime scene evidence.

Authorities have said DNA evidence also links Biela to another attack last November, when a woman was grabbed from behind and groped but managed to get away. No charges have been filed in that case.

Another attack in October 2007, when a woman was sexually assaulted at gunpoint in a garage where campus police park, may also be related, officers have said. But investigators said the victim in that case didn't immediately report the crime and no evidence was gathered.

Denison, a sophomore at Santa Barbara City College in California, was abducted while sleeping at a friend's house over winter break from school. Her purse and cell phone were not taken. Blood was left on a pillow.

Denison's body was found Feb. 15. An autopsy showed she was raped and strangled. At the scene, investigators found two intertwined pairs of women's thong underwear.

At a news conference Wednesday, Reno Police Chief Michael Poehlman said Biela left the Reno area in March to take a job in Washington state, and sold his pickup truck in Idaho along the way.

In September, his girlfriend traveled to Washington to help Biela move back to Sparks, where the couple share a home. Reno police Detective David Jenkins described their relationship as "tumultuous."

Police said when Harmon confronted Biela about finding a pair of woman's underwear in his vehicle, he claimed he had stolen them from a coin-operated laundry.

Biela, who appeared Wednesday in Reno Justice Court, requested a public defender. A preliminary hearing was set for Dec. 10.