(Vancouver, WA)  --  The search for a missing transgender teenager is ending in tragedy.  Police have arrested 27-year-old David Bogdanov on a charge of second-degree murder for the death of 18-year-old Nikki Kuhnhausen of Vancouver, Washington.  She'd been missing since June.  Investigators believe Bogdanov killed Kuhnhausen after she revealed to him that she'd been born male.  The two had reportedly been talking on Snapchat and had agreed to meet up on June 6th, which was the last day Kuhnhausen was seen alive.  Bogdanov is expected in court today.