The makers might not have wanted you to guess the killer. They might've wanted it to be a surprise for the audience.
So many stories, so little time.

Oh my bad, I heard teacher for some reason (guess I wasn't paying enough attention). That makes sense though.
The plan is you drink a nice tall glass of shut the beep up.

Loretta Devine's character talked about a disgraced teacher having to leave his old college after a murder cover up ordeal.
Loretta Devine's character didn't talk about a
teacher
having to leave another college after refusing to take part in the cover-up of several murders, she spoke about a security guard: herself. And the murders she referred to were the events of the original film.
http://hexfan.proboards.com/

Loretta Devine's character talked about a disgraced teacher having to leave his old college after a murder cover up ordeal and that was like 25 minutes in so I felt like the reveal that it in fact was a teacher who was doing it was very obvious.
I did however consider the fact that the twinbrother was not a twinbrother but the same person who died but just faked his own death in order to kill all his student-mates and was saving the blonde chick for last.
The plan is you drink a nice tall glass of shut the beep up.

Yeah, the killer's identity was a real surprise.
I've been chasing grace/ But grace ain't easy to find