The bike was stolen while thieves blocked the Vancouver couple's door early Monday morning.
On Wednesday, the couple found their bike had been returned with a note attached.
The note said: "I bring this back 2 you because I am truly sorry and I hope you can forgive me. I am trying to do the right thing."
The note was signed "guilty."
The bike was the only way for the couple to get around. They're both developmentally disabled and neither drives a car.
The suspects appeared to have been recorded on a neighbor's surveillance camera in the act of stealing the bike.
The camera captured three people heading down V Street toward the Forbes' home. Three minutes later, and moving a little faster, they can be seen going back the other way with what looks like the bike.
Police said they are still investigating the theft.
"The widespread attention to these crime victims may have contributed to the momentary activation of the suspect's conscience, however the goal of the Vancouver Police Department is to make an arrest in this case," said Vancouver police spokeswoman Kim Kapp in a news release.