From the Daily Mail:

Bias incidents at Vassar were a hoax as one of the culprits was 'the transgender student leading the investigations into the offensive graffiti' 

Six bias incidents of graffiti were reported on the school's campus 

Messages included offensive threats at transgender students and African Americans 

Claims were investigated by student-led group and school officials later realized that one of the group leaders was behind the graffiti 

Both of the students involved have left the school

This is based on reporting done by Robby Soave for the Daily Caller.