“He was quiet, for sure, but not any out-of-the-ordinary quiet like something that would alarm somebody,” said one former classmate, who declined to be named out of fear of being ostracized in Gordon, where some residents believe speaking about Mr. Patterson is a betrayal of the town. In a photo given to The New York Times, Mr. Patterson sits in a corner, alone and behind his smiling, posing classmates, absorbed with his laptop.

One of his former teachers, in a text message to a handful of Mr. Patterson’s classmates, said the man accused of the kidnapping and killings was “not the quiet, smiley, bookish boy in the classroom” she knew. “As the days pass and more news trickles out, I’ll still hold the memory of that sweet boy in my heart. His future will look very different than yours.”

[Read more about how Jayme’s disappearance shook her hometown.]

Since graduation, Mr. Patterson had struggled to hold down a job.

He worked for one day at the Jennie-O Turkey Store in Barron, where Jayme’s parents also worked. He spent two days last fall at a cheese factory. A few years before, the United States Marine Corps sent him home after five weeks of boot camp.