A 35-year-old Rutgers University graduate was stabbed to death in her New York City apartment early Sunday after a homeless man followed her into the building. Christina Yuna Lee had “trauma about the body” when New York Police Department officers found her in the bathroom of the apartment on the 100 block of Chrystie Streetin Chinatown shortly before 4:30 a.m, an NYPD spokesman said in an email. The homeless man charged with killing her — identified by New York City media outlets as Assamad Nash — was arrested a short time later after barricading himself in the sixth-floor apartment. Nash has…