State Police said their SWAT team, aided by officers from the Newberg and Corvallis police, arrested Sung Koo Kim, 30, early Saturday morning at his Tigard residence.
Bail was set at $250,000, but county jailers said his family posted the required 10 percent to free him.
Corvallis (search) Police Lt. Ron Noble said he is still only a "person of interest" but there are links that have drawn police attention.
Kim was arrested for burglary at George Fox College by Newberg Police May 13 on a search warrant that found more than 1,000 items including large quantities of womens' underwear.
He also is charged with an April burglary at Oregon State University's Sacket Hall, which is very near the site where Wilberger was last seen.
He was released on the 17th.
Noble cited the underwear theft and the proximity of Sacket Hall to the place where Wilberger, 19, was last seen as factors that raised their interest.
"He was a person of interest then and he is one now," Noble told The Associated Press.
Earlier Saturday police expanded their search Saturday for Wilberger.
Authorities asked volunteers to sign up for a search of rural roads in five counties surrounding Corvallis. About 150 people volunteered, driving slowly along the roads looking for abandoned vehicles, pieces of clothing or anything else suspicious, said Peggy Peirson, emergency services coordinator with the Benton County Sheriff's Office.
Searchers will focus on Benton, Linn, Lincoln, Lane and Polk counties, paying particular attention to routes from Corvallis to the home of Wilberger's parents in Veneta, outside Eugene, Peirson said.
About 250 other people searched on foot through an overgrown Christmas tree farm west of Corvallis, and fanned out along a railroad line near Oregon State University.
Neither group found any significant clues by around 3 p.m., Peirson said.
"We have a lot of tired people. It's a lot of searching for one week," Peirson said. "We're still grabbing for something here. I have not heard anything that has been helpful to the case."
Wilberger vanished Monday morning from an apartment complex where her sister lives, leaving behind a pair of flip-flops in a parking lot. Police said they believe she was abducted.
Noble had said Friday that searchers were more optimistic than they had been earlier in the week, but not elaborate other than to say if she were dead they likely would have found her by now.
"We feel a little better today than we did Monday, Tuesday, Wednesday," he said at a news conference Friday. "We still don't have a suspect. We don't know where Brooke is."
He said police are questioning four "persons of interest," some of whom are sex offenders.
He said he was saying all he could without jeopardizing the case and hoped a large turnout of Memorial Day volunteers would move the case forward.
"Something's going to break here pretty soon," predicted her father, Greg Wilberger. His employer is offering a $25,000 reward for information leading to the missing woman.
Noble said earlier that none of the people they are watching closely can be considered firm suspects.
"As we're looking at backgrounds, history, behavior, we are finding things that make us somewhat concerned," Noble said. "These just may be people who treat blonde, white women poorly."
He stressed, though, that those they are looking at had never had any previous contact with Wilberger.
On Friday, forensic experts had been called in to help analyze a gravel pit about four miles away from the Corvallis apartment complex where Wilberger was last seen. Searchers came across the pit at dusk on Thursday, discovering freshly dug earth and what they described as odors of oil and decay.
But further excavation of the site turned up nothing, Noble said.