In a note that he left with the memorial, the thief, signing himself off as "Bradford (the one who stole the bike)," said that he did not realize what he had taken until later, The Oregonian reported. A ghost bike is a white bicycle placed at the spot where a cyclist has been killed.
"I sincerely apologize for what I have done. I did not realize what it was until after the fact," he wrote. "I return this bike, along with one of my most cherished possessions in respect to your memorial, and as a guarantee that your efforts have impacted at least one life; mine."
Jonathan Maus, the blogger who reported the theft on BikePortland.org, said he thinks Bradford's contribution to the memorial was a blue bandanna.
"I would love to know who this guy was," he said.