I'm currently working on a book in which the protagonist has to find the owner of this certain object. It takes place in the real world not a fantasy world or anything. Is it possible for the protagonist to just take the easy route and get a fingerprint scan or something? I've read somewhere that an average person can't just go to the police to get an object fingerprint scanned and the owner located. Is that true? And if he can't, he can just report a missing person right? But how efficient will that be, exactly? And can you report a missing person for an adult? And it would be great if I'm provided by some ideas of how to find someone
I only can speak for the US, but no police agency would perform a fingerprint search for a private party even if the person is reported missing. Missing person reports are usually ignored if the missing person is an adult and has been missing less than 72 hours. A little more information about your story might help.
Not to mention everyone's fingerprints are not on file and every fingerprint data base is not necessarily in a single searchable computer file. But you could have a friend do it (illegally) as a favor if they worked for the FBI or something. Preferably a manager level so the guy/gal could get away with more.
Well, there are a lot of ways to find owners of certain objects. The most common way is by asking people around with questions like "who lived in the house I found this doll in?", "do you recognize the handwriting I found on this?", "who's name is this gun/diamond/vehicle/etc. registered under?", "do you know anyone who collects *___ objects*?" It seems to me more like your asking for "the easy route" to writing around this sub-story though. Unfortunately, there is no easy route to finding a missing adult with just an object they left behind without being unfaithful to the "real world".