The body of Whitney Heichel, 21, was found on Larch Mountain, a remote, forested area east of Gresham, Police Chief Craig Junginger told a news conference.
After collecting DNA and fingerprints and conducting three interviews over three days, police arrested Jonathan Holt, 24, of Gresham, for investigation of aggravated murder, the chief said.
Holt lived in the same apartment complex as Heichel and her husband.
The Starbucks barista reportedly left her apartment for work at about 6:45 a.m. Tuesday on a drive that typically takes less than five minutes.
Her husband, Clint, called police roughly three hours later. He told investigators he tried to reach Whitney multiple times after her boss alerted him that she never arrived for her 7 a.m. shift.
Police said Heichel's ATM card was used at a nearby Troutdale gas station at 9:14 a.m. Tuesday. Two hours later, her sport utility vehicle was found in a Wal-Mart parking lot with the passenger side window smashed.
A child later found her cell phone in a field that lies between the gas station and the Wal-Mart, giving investigators another venue to search.
Police have been searching Larch Mountain since Wednesday, believing that Heichel's SUV was driven there.
Detectives interviewed Holt on Wednesday and Thursday before arresting him during a Friday night interview, the chief said.
There were "many inconsistencies" in Holt's interviews, Junginger said.
Additional crime lab evidence received Friday morning tied him to Heichel's vehicle, the chief added.
It was not immediately known if Holt was represented by a lawyer.
Jim Vaughn, a family spokesman, addressed the Friday night news conference, thanking police for their commitment in the case.
"Really, words can't begin to express the sadness that our families are experiencing tonight," Vaughn said.
"Whitney was a very loving person," he added. "She was warm, she was kind, she was everything you would want in a friend, relative, spiritual fellow worshipper."
He asked for privacy for the family, saying "our loss and heartache is too much to bear right now."
Police took no questions.