If we are focussing purely on the essay:

If I were the teacher, I would let the student creatively express whatever they wanted. There have been great books that get into the mind of psycho killers, etc. and part of art is pushing the limits and opening society's eyes to new things or new aspects of things. Not to mention, I am the only one who is reading the essay.

If I were the principal of the school, I would not know about the essay without the permission of the student, because it is not my business what topic or form of creativity a student chooses when creative writing.

If I were the student, I would be happy I caused such a fuss, because it might mean my essay has had an effect on people and maybe opened their eyes to something new. Even if the something new was a brief look into the mind of "a creep", it would provide an understanding of another person.