If you have all the appropriate documentation and you really want to recover the bike you can. Especially if a report was filed and you have the serial number recorded and can identify unique characteristics of the bike. The PO is going to need to be certain the the bike is in fact yours and there is no ambiguity as to who the real owner is. The person that is selling the bike is most certainly not going to be charged unless the theft happened very recently. Otherwise this bike could have changed hands numerous times. You could recover the bike but do not expect an arrest. Also BE CAREFUL if you intend on confronting this person on your own and also do not forcibly take the bike from him. If you confirm that it is yours contact the police and they can assist in reconciling the situation. Good luck.