Yes, I am sure.. In the passive voice, the subject is acted upon by somebody or something. (example: kaçak, polis tarafından Ankara´da tesadüfen bulunuyor )  In the sentence "Ankara´da bulunuyor" (=> He is in Ankara) there is nobody or nothing acting upon the subject, on the contrary, the subject acts upon itself, doesn´t it?

Thank you for the explanation