"This is the weirdest case I've ever seen," said police Chief Ben McBride.
Some residents of Valentine, a town of about 2,650 people, find some humor in the strange vandalism and have taken to calling the perpetrator the "Butt Bandit." But they also can't help but cringe when finding his marks.
"We were completely grossed out," said Kalli Kieborz, who works in a downtown building. "One day I walked into the office and an employee said, 'Oh, my God, we've been struck!"' The police chief is far from amused.
"It's not funny," McBride said. "We're worried about the next step."
It started in spring 2007, when the window of a Methodist church was greased with an imprint. McBride figured it was a high school prank. But the church kept getting hit, even after police staked it out.
The bandit struck business after business, window after window last summer.
Then he - and maybe, McBride said, copycat vandals - stopped over the fall and winter.
"People said he was done," McBride said. "Then he started back up this summer."
During one particularly brazen session, virtually all the windows at a local hotel were imprinted.
McBride said no one has reported seeing the vandal in action. The only clue is a blurry picture of him caught by a surveillance camera at the middle school last year.
The man was 6-feet-tall or slightly taller, and slender. He had a dark complexion, and McBride said the man's dark hair was styled in a "1980s, feathered look."
Valentine, in remote north-central Nebraska, promotes itself as "The Heart City." Downtown sidewalks are painted with hearts, and locals encourage people from around the country to send their Valentine's Day cards to the local post office so they can be mailed out with the word "Valentine" stamped on them.
"This is not normal behavior for Valentine," Cherry County Attorney Eric Scott said. "It's not funny or something people want to be exposed to."
On the Net:
City of Valentine: http://www.valentine-ne.com/