Season 2 of the hit TV show Forensic Files included an episode (Episode 12) that contained information that those that work on missing person's cases should note. The episodes tell of the missing person's case of Dario Cicolecchia, a boy in Switzerland who went missing in 1993. Importantly, this boy was found, his murderer was apprehended, and this murderer also made statements to the police about how he operated. I think there's a nugget of information that's worth extracting from this and using as food for thought in similar cases.
Dario went missing after departing his home on bicycle to go fishing. He was later found dead and mutilated in a Swiss cornfield. Forensics was used in this case and it was discovered that the boy had been drowned. In the water in the boy's lungs, investigators found diatoms, which are simple one-cell organisms that are only found in water.
They were then able to find these diatoms in a nearby creak and that isolated the murder location. They also found the same kind of diatoms in a suspect's car, likely because the victim had been put there after he drowned. When the water seeped out of the victim's mouth, it created the potential to link victim to car to murder location to suspect.
The name of the convicted murderer was Roland Kubler. In the episode of Forensic Files, which was called "Micro-clues" and which aired on December 18th, 1997, Kubler is examined.
Importantly, he claims that what lead him to Dario was the fact that the boy had left his bicycle near the road. When Kubler drove by, he saw the bicycle and realized that it meant that a young boy was nearby. Due to his, Kubler's, instabilities he wasn't able to resist finding this boy, which eventually lead to Dario's murder.
As presented, Kubler didn't really cruise around looking for bicycles as part of a modus operandi. That's interesting because there are a lot of cases where children have gone missing with only their bicycles found. It could be that leaving their bicycles in a visible spot is part of the chain of events into what caused them to go missing. You can see how a pedophile would be 'triggered' into action when presented with a secluded area and hints of children nearby.
The missing person's case of Janice Pockett comes to mind for me. She has been missing from Tolland, Connecticut since July 26th, 1973. She owned a green bicycle that would definitely be recognized as a child's bicycle with its banana seat.
The day she went missing, she rode her bike to a wooded area with plans on retrieving a butterfly that she'd put under a rock earlier. Importantly, no one knows what happened to her after this but her bicycle was found near a road.
One scenario, with probabilities that are debatable, is that Janice left her bike by the road, entered the wooded area, and then someone drove by and saw her bike -- just like Kubler saw Dario's. An individual with problems might not be able to ignore the chance to investigate the wooded area -- just as Kubler couldn't.
The suggestions I'm making are kind of along the lines of history repeating itself. There is also an assumption that serial rapists and murderers are all somewhat alike.
There are other cases where a bicycle is found that belonged to a missing child's. That this item might be an 'advertisement' to a pedophile is something that shouldn't be ignored. It suggests a lot of things to me, especially non-family abduction and abduction by someone who is serial in nature. If you are coming across missing person's reports where a bicycle, or even a scooter or skateboard or something else of that nature that implies 'young person nearby,' then think about the visibility of the object and how it might be something that a pedophile or kidnapper really notices.
This could be a solid basis with which to start some reasonable conjecture. To me, it suggests that the victim was pursued rather than the victim stumbling onto something.